Guarantee period

The Vendor shall be fully responsible for the trouble-free operation of the flare system constructed by him throughout the entire guaranteed period.  [c.315]

Many disputes arise in this first year if the installation is not maintained to the satisfaction of the supplier, and a split responsibility of this sort is to be avoided. As already stated, where possible, maintenance for the first 12 months should be by the original contractors or a firm recommended by them. There is a growing tendency to extend the guarantee period on small packaged plant to 3 years.  [c.345]

As a consequence of the heterogeneity of composite materials, initial defects are difficult to be eliminated completely. To guarantee the structural safety of these materials it is necessary to investigate the effects of their defects under service conditions. When a composite material is loaded, different types of damage will occur matrix cracking, delamination fibre/matrix debonding and fibre failure. Some of these damage types will initiate even at a very low load level, without causing overall failure of the composite part. However, during further loading the initial damage will grow and create other types of damage. The fatigue damage accumulation in fibre reinforced composite materials can be evaluated by different Non Destructive Testing (NDT) techniques. The most commonly used NDT techniques to date have been the ultrasonic C-scan and the x-ray radiography for detecting primarily internal delamination and matrix cracking respectively. Nevertheless, an interruption of the fatigue loading and removal of the specimen from the test fixture is usually required, which may affect the fatigue results.  [c.45]

Thus, to proeeed downhill in all direetions (sueh as one wants to do when searehing for loeal minima), one ehooses eaeh Xa in opposition to ga and of small enough length to guarantee that the magnitude of Xa ga exeeeds that of 1/2 x a for those modes with > 0. To proeeed uphill along a mode with Xa <0 and downhill along all other modes with Xa > 0, one ehooses Xa along ga with Xa short enough to guarantee that Xa ga is larger in magnitude than 1/2 x a a, and one ehooses the other Xa opposed to ga and short enough that Xa ga is larger in magnitude than 1/2 x a a-  [c.518]

Being involved in teaching and directing research work for half a century, I always felt that mentoring my younger colleagues was an essential part of my responsibilities. In a way, one of the best judgments of any professor is how his students or associates feel about him and also how they fare in their own careers. It is not unlike how parents feel about their children. To observe with satisfaction and pride the achievements of your scientific family, which in a way is also the continuation of your own work, is most rewarding. Because I was never associated with one of the leading universities, having also spent some of my career in industry, my graduate students usually came from more modest schools than those of their peers who have gone to our premier colleges and universities. This is quite understandable and based on sound reasons. Going to Harvard, Stanford, MIT, or Caltech to earn a graduate degree in itself usually guarantees a good chance for a successful career. On the other hand, motivation and desire also count  [c.248]

In the United States the analytical methods approved by most states are ones developed under the auspices of the Association of Official Analytical Chemists (AOAC) (3). Penalties for analytical deviation from guaranteed analyses vary, even from state to state within the United States (4). The legally accepted analytical procedures, in general, detect the solubiUty of nitrogen and potassium in water and the solubiUty of phosphoms in a specified citrate solution. Some very slowly soluble nutrient sources, particularly of nitrogen, are included in some specialty fertilizers such as turf fertilizers. The slow solubihty extends the period of effectiveness and reduces leaching losses. In these cases, the proportion and nature of the specialty source must be detailed on the labeling.  [c.214]

Preparation and Protection of the Parts. One, if not the most, important technological step to guarantee success of a joining operation is the preparation of the parts to be joined. Cleaning part surfaces of oxide films, oil, grease, and dirt includes mechanical and/or chemical means, solvent usage, and, finally, rinsing and drying. If not properly cleaned, the joined assembhes may leak or lack the necessary strength owing to incomplete joining  [c.246]

Where storage stabiHty and convenience are important considerations, ADY has largely replaced compressed yeast. The yeast is packaged in hermetically sealed aluminum foil pouches for domestic use, in 0.45—0.91 kg cans for institutional use, or in 10-kg foil pouches. Since a minimum storage life of 1 year is guaranteed, the yeast is packed in a nitrogen atmosphere or under vacuum, and the integrity of the package is at least as important as the original activity of the yeast. For use in wholesale bakeries, active dry yeast is usually deHvered in polyethylene-lined dmms and is not protected by an inert atmosphere accordingly, it should be used within 2—3 months. The yeast requires separate hydration in water, preferably at 35—40°C before addition to other dough ingredients. A period of 5—10 minutes is sufficient for full rehydration and optimum activity.  [c.389]

The algorithm requires only a single force evaluation per integration cycle (computationally, force evaluations are the most expensive part of the simulation). This formulation, which is based on forward and backward expansions, guarantees time reversibility (a property of the equation of motion).  [c.46]

EPA has 45 days to review each permit and to object to permits that violate the CAAA. If EPA fails to object to a permit that violates the Act or the implementation plan, any person may petition EPA to object within 60 days following EPA s 45-day review period, and EPA must grant or deny the permit within 60 days. Judicial review of EPA s decision on a citizen s petition can occur in the federal court of appeals. The public is guaranteed the right to inspect and review all permit applicahons and documents. There are provisions for three kinds of permit revisions administrative amendment, minor permit modification, and significant modification.  [c.403]

The performanee tests must be run as mueh as possible to meet the ASME performanee eodes. These eodes are very well written and fully delineate the tests required. Meetings should be held in advanee with the vendors to deeide whieh part of the eode would not be valid and what assumptions and eorreetion faetors must be undertaken to meet the various power and effieieney guarantees. The determination of speeial data or verifieation of partieular guarantees, whieh are outside the seope of the eodes, should be made only after written agreement of both parties to the test, espeeially regarding methods of measurement and eomputation, whieh should be eompletely deseribed in the test report.  [c.148]

Composite materials have greatly increasing popularity in the aerospace industry during the last quarter century and adhesive bonding is an integral part of composite part manufacture for various reasons. The matrix polymer for a given composite system, whether it is epoxy, bismaleimide or polyimide, can usually be formulated into a suitable adhesive. This virtually guarantees chemical compatibility and good adhesion between the adhesive and matrix resin. Also, composite materials are not high in fastener bearing strength and are prone to damage during hole drilling, meaning that mechanically fastening composites is laborious and disadvantageous. Lastly, fabrication processes to mold and cure composite parts are virtually identical to necessary to cure adhesive bonds. Many times the two operations can be combined, achieving great savings in fabrication costs.  [c.1132]

Product qualification versus consistency control and design values. Engineering property requirements such as those discussed above are used for two separate and distinct purposes, both of which have little to do with the actual performance expected of the adhesive in a real part. Adhesives requirements in a specification are used for both initial product qualification and batch consistency control. New products are tested to the requirements of the specification, or qualified, in order to determine whether it meets those requirements. The requirements are relatively limited in scope and test configurations are simple and not typically representative of actual part designs. Qualification serves to indicate whether the product in question has the properties required to justify further effort. For new specifications that push available technology, this process is often iterative, with requirements raised or lowered (within limits) to match the product that is available. For existing specifications, the qualification merely serves to indicate that the product is equivalent or better than the existing qualified materials. The same requirements are then used to guarantee batch to batch consistency for ongoing production. Governmental agency regulations for aircraft require a manufacturing control system that guarantees consistent quality of materials and processes. As applied to adhesives, that means that there must be certainty that a new batch of  [c.1150]

The basic requirements to be satisfied by the mixer are that the entire contents of the tank be mixed and that the mixing be completed within the desired time period. Consideration of the entire contents arises because if fluid batches of different densities are added to a tank, it is possible to form stable layers of the different batches. This is known as stratification. In a stratified tank, mixing accomplished by a mixer physically located in one layer does not guarantee mixing throughout the entire tank. The differing fluid densities which lead to stratification can be caused by differences in temperature or composition. In the case of LNG and LPG, which can vary in composition, it is possible to add a dense layer to the bottom of a tank which upon warm-up during storage can become less dense than the upper layer resulting in a "roll-over" of the tank contents. This can result in dangerously high vapor release rates due to spontaneous flashing of the warm layer which is suddenly exposed to reduced pressure at the surface of the tank. For operations where stratification can potentially occur, tank operating procedures and mixer design should be selected so that stratification will not occur. Once a tank becomes stratified, unusually high mixing energy is required to break the stratification.  [c.467]

The reader should note that although the author has made every reasonable attempt to verify the accuracy of the information compiled in this volume by a review of multiple open literature sources, there are no guarantees as to the accuracy of information, and we do not recommend or endorse the application of this information for design purposes or emergency response procedures. This handbook provides guidance only, and much of the information and data will require interpretation and prudent judgement on the part of a knowledgeable reader with training in chemistry, engineering, and safe handling procedures for hazardous chemicals.  [c.439]

Another way to utilize LCC calculations is in support of a purchase. The supplier can offer both the purchase price and an estimate of the present value of the life cycle operating costs At the same time the supplier guarantees the operating cost for some period, for example, 3 years. If these target costs are exceeded, the supplier pays a penalty, and if the operating costs were overestimated, the supplier and the customer share the bonus.  [c.1373]

The tender with the lowest total costs (sum of investment, energy and maintenance costs) is the best and the supplier guarantees energy, and maintenance costs for, say, a three-year period. If the target costs are exceeded, the supplier pays a penalty if the operating costs are lowered, the supplier and the customer share the bonus.  [c.1379]

Since 0 < c < 1 the first term shows that UHF orbitals reduce the ionie eontribution relative to the covalent structures, compared to the RHF ease, eq. (4.18). This is the same effect as for the Cl procedure (eq. (4.19)), i.e. the first term shows that the UHF wave funetion partly ineludes electron correlation. The first term can be written as a linear eombination of the 0 and 1 determinants, and deseribes a pure singlet state. The last part of the UHF determinant, however, has terms identical to two of those in the triplet eombination (4.22). If we had ehosen the alternative set of UHF orbitals with the alpha spin being primarily on eentre B in eq. (4.20), we would have obtained the other two terms in i.e. the last term in (4.24) breaks the symmetry. The UHF determinant is therefore not a pure spin state, it eontains both singlet and triplet spin states. This feature is known as spin contamination. For c = 1 the UHF wave funetion is identical to the RHF, and is a pure singlet. For c = 0 the UHF wave funetion only contains the covalent terms, which is the correct dissociation behaviour, but also contains equal amounts of singlet and triplet character. When the bond distance is very large, the singlet and triplet states have identical energies, and the spin contamination has no consequence for the energy. In the intermediate region where the bond is not completely broken, however, spin eontamination is important. Compared to full Cl, the UHF energy is too high as the higher-lying triplet state is mixed into the wave funetion. The variational principle guarantees that the UHF energy is lower than or equal to the RHF energy (there are more variational parameters). The full Cl energy is the lowest possible (for the given basis set) as it recovers 100% of the correlation energy. The UHF  [c.113]

For unresolved peaks eluting from the first column into the modulator, each pulsed solute packet delivers a group of components to column 2. It does this every modulation event, e.g. every 4 s. There is no guarantee that each solute will have a retention less than the modulation time, and so some peaks may not have reached the detector by the time the next packet of solute is launched into the short fast second column. The procedure for generation of the matrix format is illustrated in Figure 4.10. The column data are taken in blocks of data points equal to the number of points corresponding to the modulation time, and put into a column. This procedure is repeated until the full data are transformed. If a peak from one modulation event happens to be retained longer than the sampling period, then it will not be included in that period s transformed data block. Let us say the solute has a 2D retention time of 5 s. Since the data are transformed into matrix form for 2D presentation, using the 4 s modulation time as one matrix edge, then the 5 s retained solute will have an apparent transformed time of 1 (= 5-4) s, and its peak will appear to be centred on a time of 1 s in the 2D plot. Thus, while we normally use the labels first dimension retention (which is correct) and second dimension retention for the 2D space, the above solute does not have an absolute retention of 1 s on the second column. (It may be more appropriate to say apparent retention or use a similar term to reflect that the time does not necessarily have an absolute meaning on the 2D axis.) Here, the solute has wrapped around one set of matrix transformations of data and so appears in the subsequent matrix data line. It is possible to have solutes wraparound more than once. A useful way to decide if wraparound occurs is to study peak widths in the second dimension. Those peaks retained more will have increasingly wide peaks. In a recent study, for instance, of derivatized sterols (24), the high elution temperature meant that the sterols eluted during the isothermal hold period (at 280°C). Thus, the later peaks not only became increasingly broad in the first dimension, but because they were less volatile they were more retained on the second column. A modulation of 4 s was used, and the last sterol had a time of  [c.92]

Chemical development Proof of structure and configuration are required as part of the information on chemical development. The methods used at batch release should be validated to guarantee the identity and purity of the substance. It should be established whether a drug produced as a racemate is a true racemate or a conglomerate by investigating physical parameters such as melting point, solubility and crystal properties. The physicochemical properties of the drug substance should be characterized, e.g. crystallinity, polymorphism and rate of dissolution.  [c.325]

State regulation during this period continued the trend of promoting nonutility sources of generation. While PURPA was passed by the federal government, it was the responsibility of state regulators to set the rates at which utilities were required to purchase cogenerated or QF power. In response to the energy crisis of the period, state regulators began to set overly generous rates for QF power to stimulate consei vation and alternative sources of electricity in a period of uncertainty. As a result of the generous rates and guaranteed market for nonutility generated power, generating capacity from nonutilities increased from close to 2 percent in 1978 to over 8 percent a decade later.  [c.411]

For most applications the efficiency will be 98-99 percent plus as long as the range of operating velocity is observed. The typical performance curves for this type of material are given in Figures 4-17B, 4-18, and 4-19. For hydrocarbon liquid-natural gas system, guarantees are made that not more than 0.1 gallon of liquid will remain in the gas stream per million cubic feet of gas. Special designs using a 3-foot thick pad reduce radioactive entrainment to one part per billion [21].  [c.250]

The exploration activities directed at locating new petroleum-producing provinces are cost-intensive operations. The capital expended in the search for new petroleum-producing provinces is always at risk because there are no guarantee that such searches will be economically successful. There is no way to actually know if crude oil or natural gas is present in a particular geologic formation except to drill into the formation and physically test it. Highly sophisticated geologic and geophysical methods can be used to identify the possible subsurface geological conditions that might contain crude oil and/or natural gas. However, the final test is to drill a well to the rock formation (reservoir) in question and physically ascertain whether it contains petroleum, and if it does, ascertain if the petroleum can be produced economically. Thus, in the early part of the exploration phase geologists, geochemists, geophysicists and petroleum engineers must form teams in order to carry out effective investigations of possible petroleum producing prospects [68]. In general, such teams are initially driven by the geologic, geochemical and geophysical sciences that are to be used to infer possible subsurface locations for new deposits of petroleum. However, once the subsurface locations have been identified, the process of discovery becomes driven by the necessity to drill and complete a test well to the prospective reservoir. The skills of the exploration geologist are important for successful drilling. These exploration (wildcat) wells are usually drilled in remote locations where little or no previous subsurface engineering experience is available, thus, they are inherently risky operations.  [c.365]

Period of guarantee from contractual documents  [c.96]

Once the operation of the unit has lined out, it is time to conduct a series of test runs to compare performance and economic bend its of the unit with what was projected as part of the original project justification. The results can also be used to determine if the unit s performance meets or exceeds the engineering contractor s performance guarantee.  [c.212]

Various types of contract are offered and it is recommended that the original suppliers are approached during the commissioning period (or before) for their suggestions. In particular, there may be friction if a rival firm undertakes maintenance while the plant is under guarantee and it is usual to let the first year s contract to the installer.  [c.343]

This case is particularly interesting for two reasons. First, time-periodic potentials such that arise from external periodic forces, frequently give rise to cyclically varying states. (According to the authors of [253] The universal existence of the cyclic evolution is guaranteed for any quantum system. ) The second reason is that the Fourier expansion of the cyclic state spares us the consideration of the convergence of the infinite-range integrals in Eqs. (9) and (10) instead, we need to consider the convergence of the (discrete) coefficients of the expansion. In this section, we show that in a broad class of cyclic functions one-half of the complex t plane is either free of amplitude zeros, or has zeros whose contributions can be approximately neglected. As already noted, in such cases, the reciprocal relations connect observable phases and moduli (exacdy or approximately). The essential step is that a function [c.120]

The symplectic method LIM2 [41] was further explored in [67] with the thought that it might alleviate resonance in comparison to IM. It turns out that the parameter a affects the relationship between the numerical frequency and the actual frequency of the system. Specifically, the maximum possible phase angle change per timestep decreases as the parameter a increases. Hence, the angle change can be limited by selecting a suitable a. The choice Q > restricts the phase angle change to less than one quarter of a period and thus is expected to eliminate notable disturbances due to fourth-order resonance. The requirement that a > guarantees that the phase angle change per timestep is less than one third of a period and therefore should also avoid third-order resonance for the model problem. This was found to hold in our application to a representative nonlinear system, a blocked alanine residue [67]. Namely, the energy averages increase with At but exhibit no erratic resonance patterns for LIM2 as did IM (Fig. 9). Unfortunately, these energetic increases are not acceptable (e.g., approximately 30% and 100% of the small-timestep value, respectively, for At = 5 and 9 fs for this system). Part of this behavior is also due to an error constant for LIM2 that is greater that of leap-frog/Verlet.  [c.244]

Unfortunately, there is no set recipe that guarantees adequate coverage of phase sp and thus reliable free energy values [Mitchell and McCammon 1991]. The errors associa witii inadequate sampling may be identified by running the simulation for longer period time (molecular dynamics) or for more iterations (Monte Carlo) the perturbation can performed in both forward and reverse directions a different scheme could be usee determine the free energy difference (e.g. thermodynamic perturbation and thermodynai integration). At the very least, the simulation should be run in both directions the differe in the calculated free energy values (often referred to as the hysteresis) gives a lower-boi estimate of the error in the calculation.  [c.593]

Although CR continues to have about the same production volume, its share of total elastomers production has dropped from around 5% in 1975 to 3% in 1989 (2). In part, this is related to the introduction of new materials that may not match CR s balance of properties but work quite well in specific areas and are less expensive. For a typical compound, CR s cost is about twice that of EPDM. AppHcations that require only weatherabiHty and heat resistance tend to move to the less expensive product. Use of polyetheresters, eg, HYTREL, in CV-J boots replacing CR, is based on a combination of an easier process and improved quaHty (impact resistance) with a more modem and much more expensive material. Another difficulty facing CR has to do with changes in product requirements. Longer automotive guarantee periods together with higher underhood temperatures will place more stringent requirements on the heat resistance of all underhood parts. This may result in partial replacement of CR in some underhood appHcations.  [c.549]

State and federal tax subsidies and loan guarantees fueled the growth of fermentation ethanol capacity in the early 1980s. In 1980, loan guarantees of nearly 342 x 10 from the Farmers Home Administration were approved for 15 new plants in 14 states to produce 931 x 10 L per year for fuel as part of the synfuels program (189). In the mid-1980s the phase-out of lead as an octane enhancer in gasoline kept the fuel ethanol program aUve. The 1990 Clean Air Act requirements for oxygenates and renewal of the Federal tax rebates worth 0.16 per Hter of ethanol pumped new life into the fuel ethanol program in the late 1980s. The estimated 1991 demand for fuel ethanol was over 3.0 X 10 L (190).  [c.408]

The early period. In the 1950s and 1960s, Al was mostly concerned with developing computer programs that could perform tasks that were considered to requke a high degree of intelligence, eg, game playing in domains such as chess and checkers (7) the solution of logic problems, such as theorem proving (8) and the solution of puzzle problems in toy domains (9). One key development of this period was the idea of heuristics, an important precursor to expert systems. Heuristics can be defined as guidelines for choosing among alternative courses of action. Heuristics can be used as shortcuts to dkect the search for a solution along more promising lines, even if an optimal solution is not necessarily guaranteed. Another key development of this period was the creation of Lisp, a symboHc programming language.  [c.530]

The farmer has inevitably been blamed for most of the nitrate problem, but we should not forget the contribution of the politician. The Treaty of Rome, signed in 1957, committed the six founder members of the European Community to the Common Agricultural Policy, and thence to the expansion of agricultural production and productivity through the provision of a guaranteed market for produce. This brought many social and economic benefits, but it led inevitably to the intensification of agriculture, and increased use of nitrogen fertilizer was a necessary part of the intensification package. When nitrate concentrations increased in natural waters, the EC introduced the 50gm limit for nitrate in potable water in 1980, thereby putting the onus for solving the problem on farmers and water suppliers. It should perhaps have reviewed the Common Agricultural Policy at the same time.  [c.25]

The seeond method of overeurrent proteetion is pulse-to-pulse overcurrent protection. This method guarantees a maximum safe power switeh eurrent. A eurrent sensing element (resistor or eurrent transformer) is plaeed in series with the power switeh(es). It views the instantaneous eurrent flowing through the power switeh and will instantly eutoff the power switeh if a preset instantaneous eurrent limit is exeeeded. This eireuit must be very fast and will proteet the power switeh from all forms of instantaneous overeurrents ineluding eore saturation. It is not a form of eurrent-mode eontrol sinee this proteetion limit is fixed and not infiueneed by external parameters.  [c.73]

Voltage Hysteretic Control. This is what people used to call hiccup-mode. A simple comparator is used to view the output voltage. If the voltage falls below a certain limit, the PWM loop turns on for a period of time until this limit is surpassed (plus some hysteresis voltage). It guarantees that the output voltage ripple is equal to or greater than the amount of hysteresis voltage in the control circuit.  [c.74]

Having a rating less than a 200 W has many benefits for a power faetor eorree-tion stage. The major benefit is that it ean operate in the diseontinuous-mode. Within higher power PTC designs the eontinuous-mode must be employed whieh presents a signifieant loss within the eireuit due to the reverse reeovery time of the output reetifier. In fixed frequeney diseontinuous-mode PTC eon-trollers, there is still a period when the eireuit operates in the eontinuous-mode (Vin < 50 V (approx.)). By employing a critical conduction-mode eontroller, the designer ean guarantee that the eontinuous-mode is never entered.  [c.225]

The principles and strategies of retrosynthetic analysis facilitate the discovery of possible synthetic pathways to a complex target structure. Exhaustive and systematic analysis over a period of time generally reveals a surprisingly large number and diversity of such candidate routes. Such extensive analysis, which is a prerequisite in modem synthetic planning, leads to an important phase of synthesis which may be described as the evaluation of alternative synthetic pathways to assess relative merit. The first step in this evaluation is the critical analysis of each possible synthetic pathway in the synthetic direction in detail in order to estimate the potential success and efficiency of each step. It is then necessary to derive for each pathway an optimum ordering of the individual synthetic steps since the best ordering cannot be ascertained (and is certainly not guaranteed) during initial generation of a retrosynthetic sequence, and is only possible after the derivation of a complete pathway. Alternative orderings of the same steps usually differ in merit because the efficiency of individual reactions, the need for protective groups or activative groups, stereoselectivity, and interference by reactive functionality all vary with the precise structure of a reaction substrate. In general an ordering which promises better overall yields, fewer control steps (protective or activative), more practical reagent requirements, and higher certainty of successful execution, is much to be preferred.  [c.78]

The first term is referred to as the diamagnetic contribution, while the latter is the paramagnetic part of the magnetizability. Each of the two components depend on the selected gauge origin however, for exact wave functions these cancel exactly. For approximate wave functions this is not guaranteed, and as a result the total property may depend on where the origin for the vector potential (eq. (10.61)) has been chosen.  [c.250]

Attack on the substrate in low pH conditions, e.g. when covered in mud or marine growth, prior to energising, has been found to be a possible cause of failure - . A commercial guarantee requires that the period in which anodes remain unenergised must not be longer than 8  [c.167]

See pages that mention the term Guarantee period : [c.345]    [c.231]    [c.148]    [c.322]    [c.442]    [c.455]    [c.1176]    [c.5]    [c.1172]   
Refrigeration and Air Conditioning (2000) -- [ c.345 ]