False starts

Assistance in problem definition and in developing a test program should be sought from persons experienced in the field. If your organization has a consultant in separations of this land, by all means m e use of the expertise available. If not, it may be wise to employ an outside consultant, whose special knowledge and guidance can save time, money, and headaches. It is important to do this early after the separation equipment has been installed, there is httle a consultant can do to remedy the sometimes disastrous effects of a poor selection. Often it is best to work with established equipment manufacturers throughout the selection process, unless the problem is unusually sensitive or confidential. Their experience with problems similar to yours may be most helpful and avoid many false starts. 

Regardless of the implementation strategy you select, try to build in at least some degree of local involvement in planning and implementation. Local involvement can give facility personnel "ownership" of the process, meaning that they will be more likely to work to overcome any problems or false starts. In addition, local participation means that you will be able to identify any local barriers to implementation—sooner rather than later. 

It seems there is no problem in modern physics for which there are on record as many false starts, and as many theories which overlook some essential feature, as in the problem of the thermal conductivity of nonconducting crystals (Peierls, 1961). This statement by R. Peierls goes back to almost 50 years ago, yet it appears to be still valid. Compared with charge flow (electric current), much less is known about the heat flow. 

In 1978, on the basis of a few measurements of urine calcium and phosphate excretion as well as an awareness of the previously mentioned work regarding the amounts of calcium and phosphate normally accreted in utero and postnatally, it became apparent that the demineralization, fractures and rickets we were seeing in our infants were caused by calcium deficiency. Consequently we increased the amount of calcium added to the parenteral alimentation solutions. If more than 12.5 mM of the calcium were added to a liter of hyperalimentation solution, gross precipitation would occur in the feeding solution. If 10 mM of calcium were added per liter, crystalline precipitated began to build up on the inside of our barium-impregnated silicone rubber central venous catheters. This crystalline precipitate resulted in gradual occlusion and functional loss of these lines. After several false starts and six lost catheters, chemical and crystal analysis showed that the precipitate inside these catheters was CaHPO. ... 

So the industry has completed 5 years of life under TSCA. We are still in business. But we have changed. Some of the changes come from responding to the law. Some of our responses are to the "spirit of TSCA" — the public demands for responsive action that created the political atmosphere in which TSCA was originally conceived. From the EPA, we have seen several false starts in getting their act together. 

Organize your data Into one or more sets of results. (Omit results that led to false starts or dead ends or that were preliminary in nature.) What evidence does each set of results reveal Organize the sets of results in a logical sequence so that the pieces ofevidence lead ultimately to the conclusion(s) of your work. (Remember that you do not need to follow the actual order In which the data were collected.)... 

Results may appear to be presented in chronological order, but usually they are not. Actual chronological order is often quite messy because of false starts, dead ends, and "wrong turns." True chronological order only confuses the reader. 

The MCS is a stretch of unique restriction endonuclease cleavage sites between the promoter and the poly (A) signal in expression plasmid vectors, and is used as a common area to insert a cDNA or gene of interest. By using the MCS, the genes of interest can be inserted and assayed with ease. Sticky-end and blunt-end vector strands are available at different restriction sites. Although the MCS is very convenient, it should be noted that these sites usually remain in the mRNA transcribed from the expression unit of the vector and may reduce its stability or the efficiency of translation. Furthermore, one must be careful not to produce an ATG codon at the junctional sequence between the MCS and the insert, because it may work as a false start codon in the resulting mRNA and interfere with the production of the correct product. 

Figure 1 Individual PVT reaction times (msec) for a representative subject undergoing 88 hr (3.67 days) of total sleep deprivation. Reaction times are from the 10-min visual PVT test bouts at 20 00 on each day of deprivation at 12, 36, 60, and 84 hr of sustained wakefulness. Reaction times after presentation of each stimulus are represented by black bars. Blank spaces between reaction times represent false starts (errors of commission). Reaction times > 500 msec are termed performance lapses, or lapses in attention. After 12 hr of wakefulness, reaction times were comparable across the test bout, with no false starts. At 36 hr of wakefulness, there were occasional lapses in attention (RT > 500 msec), with some false starts near the end of the test bout. After 60 hr awake the frequency of performance lapses was increased a few minutes into the performance bout. At 84 hr of sustained wakefulness, there were significantly more lapses of attention, with RTs > 8000 msec, and a greater incidence of false starts. (From Ref. 44.)...

Figure 3 Mean PVT reaction times (msec) and false starts (errors of commission) during 88 hr of total sleep deprivation and 88 hours of sleep deprivation with two 2-hour nap opportunities each day. Subjects in the total sleep deprivation (TSD) group (n = 13) are represented by the open circles. Subjects in the 88-hr sleep deprivation plus two 2-hr nap opportunities (NAP) group (n = 15) are represented by the closed squares. Nap opportunity periods were at 02 45-04 45 and 14 45-16 45 each day. The top panel illustrates mean reaction times ( s.e.m.) for each test bout across the experimental protocol. Subjects in the NAP group demonstrated little variation in reaction times across the experimental period, while subjects in the TSD group experienced significant impairment in performance, reflected in the increasing reaction times as time awake increased, with circadian variation in performance capability evident. The bottom panel illustrates mean number of errors ( s.e.m.) per test bout across the experimental protocol. A similar pattern of performance degradation in this variable was evident for both the NAP and TSD groups. (From Ref. 44.)...

The studies of the biosynthesis of erythrina alkaloids got off to a false start. In a beautiful experiment, A. I. Scott and colleagues showed49,50 that the whole erythrina skeleton could be constructed in one simple phenolate coupling radical reaction. 

Finally, the successful sequestration of massive quantities of carbon may be essential for any hydrogen economy that makes more than transitional use of carbonaceous fuels. The history of radioactive waste disposal suggests that dedicated opposition can overcome general public acceptance of a technology and its waste disposal plan. Thus, even energy systems that now appear to enjoy widespread acceptance can become vulnerable to delays and costly false starts. The carbon sequestration issue falls into that category (see Chapter 7). 

Complexes containing the Rh—02 moiety are now well known, but there have been a few false starts and misunderstandings along the way. The first claim for an 02 complex of rhodium was made by Wilkinson and co-workers,1141 who reported that [Rh(H)(CN)4(H20)]2 reacted with 02 to give the peroxide-bridged dimer [(H20)(CN)4Rh—02—Rh(CN)4(H20)]4. This was later disputed, and the reaction product identified as the protonated, peroxo monomer of Rh111, [Rh(02H)(CN)4(H20)]2. 1142 The solid is diamagnetic, and displays O—O stretches at 839 and 825 cm-1, characteristic of an unsymmetric monomer no such bands appear in the Co-peroxo dimer.1142. 

Wasted design hours due to false starts and recycles. 

A well-thought-out and timely issued project execution plan chooses the most cost-effective route and avoids costly vacillations, false starts, and unexpected changes in direction. It anticipates and avoids pitfalls and plans alternate routes for the blatant ones. 

Kobayashi (22) performed computer simulations via Eq. (4) as applied to his differential fixed-bed reactor. The model gas-phase reaction X Y is considered to pass in series through elementary steps to adsorbed X, an adsorbed intermediate in, adsorbed Y, to give finally Y. The forward and backward rate parameters were adjusted to simulate various mechanisms with their rate-determining steps. The shapes of the response curves for Y for typical mechanisms arc classified as instantaneous, monotonic, overshoot, S shaped, false start, and complex. This paper is a good so urce of ideas for the interpretation of transient responses. These ideas are illustrated by application to the oxidation of ethylene over a silver catalyst (23). The response curves last more than 100 min because the temperature is only 91°C and the bed contains 261 g of catalyst the flow rate is 160 ml/min. 

Fig. 39. The large graph is a curve of the steady-state rate of CO2 production as a function of Pqo over K25-ZnO at 150°C and P02 = 0.2 bar. The CO2 transient response curves (a)-(e) result from stepwise changes of the CO pressure among the points A-E as shown above the response curves. The response modes are classified as (a) monotonic, (b and c) complex, (d) false start, and (e) overshoot (after 222).

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