Controlled atmosphere (CA) storage of horticulture crops involves the holding of such produce in refrigerated storage with a reduction of oxygen and an increase in carbon dioxide. The effect of controlled atmospheres on the keeping quality of Centennial, Jersey, Goldrush, Nemagold, Oklamar, and Porto Rico sweetpotato varieties was studied in the 1963-65 period. Evaluations were made of decay loss, weight and dry matter loss, soluble solids percent, carotene content, taste of raw and baked roots, keeping after storage, and the ability of roots to sprout. In 1963-64, ranges of carbon dioxide from 0 to 15 percent were used in combination with 2 to 16 percent oxygen. Sweetpotato roots stored under atmospheres having an oxygen level below 7 percent or a carbon dioxide level above 10 percent developed a high percent of roots with either an alcoholic flavor or an off-flavor. Sweetpotatoes under an atmosphere of 3 percent carbon dioxide and 7 percent oxygen (3-7) had better quality than check lots as evaluated by low total losses due to decay and weight loss, higher dry matter content and a low dry matter loss, high total soluble solids and a high percent of acceptable tasting roots. The only disadvantage of this CA treatment was a higher loss due to decay upon holding at room temperature for one month after storage. However, this high loss was not significantly different from the open air check. In 1964-65 controlled atmosphere levels of 2 to 7 percent carbon dioxide in combination with 7 to 11 percent oxygen were used. Results similar to those of 1963-64 were obtained in 1964-65. Sweetpotatoes under an atmosphere of 2-7 in a gas generated CA room, had better storage quality as measured by low total losses, low dry matter disappearance, higher total soluble solids and a high percent of acceptable tasting roots compared to the checks. Roots removed from CA in 1964-65 and held at room temperature for one month did not exhibit the high decay found in the 1963-64 season. Decay was slightly higher than the check but not significantly different. The 2-7 atmosphere did not impair sprouting when roots were held at a warm temperature after storage. Sweetpotato roots under a 3-8 atmosphere in a sealed 55 gallon drum were relatively similar to roots held in the 2-7 room atmosphere, but were generally poorer in keeping quality. Sweetpotatoes under atmospheres 7-8 and 3-11 had lower total losses compared to the room air or open check, but not the covered drum check. Roots under these controlled atmospheres were not different from the covered check in dry matter loss and were higher in soluble solids, carotene content and percent acceptable tasting roots than the open check. Roots removed from the 7-8 and 3-11 atmospheres had higher decay losses than the checks after holding at room temperature for one month. The 7-8 and 3-11 atmospheres significantly decreased the ability of roots to sprout at room temperature. There were pronounced varietal responses to controlled atmosphere storage. CA holding had a beneficial effect on the Centennial and Jersey varieties and to a lesser degree on the Porto Rico and Goldrush varieties as evaluated by reduction of total losses, dry matter loss, higher soluble solids levels and a higher percent of acceptable tasting roots. More off-flavor developed in roots of the Nemagold and Oklamar varieties. The Nemagold and to a lesser degree the Oklawar had a higher total loss, dry matter loss, and lower soluble solids than the other varieties and after removal from CA and holding at room temperature the Nemagold variety developed more decay. / Ph. D.

Pestalotiopsis westerdijkii, a cellulolytic mold, exhibited the production of a freely diffusing, extra-cellular enzyme capable of solubilizing hydrocellulose and amorphous cellulose when grown on coconut flour-solka-floc (2:1) medium at 31°c for 11 days. For the first time, the pH and temperature optimum for the maximum activity of the enzyme was established. The potency of the enzyme increased by serial culturing of the mold on the same medium. Activation of enzyme by cysteine hydrochloride was observed. Five-fold increases in specific activity with the elimination of most of the non-enzymic nitrogen was achieved by (NH₄)₂SO₄ precipitation and gel filtration of the crude enzyme. The enzyme treatment of coconut flour brought marked improvement in protein extractability with a corresponding decrease in crude fiber. This action of the enzyme was further established by the increase of water-soluble reducing sugars in the enzyme-treated milk due to the degradation of structural polysaccharides. The amino acid composition or the control residue predicted ample room for possible improvement of the amino acid pattern in the enzyme-treated milk. The most limiting amino acids in the coconut milk preparation is lysine in confirmation of Butterworth and Fox (4), and Thomas and Scott (41) 1 followed by threonine, the sulfur amino acids and isoleucine. Significant amounts of threonine and isoleucine were stripped out of the control residue by the enzyme treatment, and the order of limitation became lysine, the sulfur amino acids, isoleucine and lastly, threonine. The animal feeding experiments did not show any significant difference between the protein qualities of the control and enzyme-treated milk preparations; however, the animals on the residue diets all lost weight. Those which were on enzyme-treated residue did very poorly. Low digestibility of the enzyme-treated residue reflected by the restricted protein intake due to high fiber content, and the presence of the sub-optimal levels of essential amino acids compared to the control residue resulted in great loss in weight, bloated appearance and loss of balance at the end of the experimental period. The enzyme appears to be nontoxic. The enzyme at its optimal pH and temperature solubilized hydrocellulose yielding oligosaccharides with an average degree of polymerization of eleven. Also, the enzyme was more capable of handling cellobiose through cellohexaose than the higher oligosaccharides to form glucose. The wide substrate specificity exhibited by the enzyme resulted in extensive degradation of pieces of Whatman No. 1 filter paper and certain vegetable foodstuffs. / Ph. D.

The Lincoln Electric Company has been outstandingly successful in the manufacture of welding equipment. The purpose of this thesis is to examine the overall personnel program of the Lincoln Electric Company, and to relate various segments of this program to the high level of individual and organizational productivity which is evident at Lincoln. As a consequence of this study, numerous conclusions were reached. First, many policies in effect at the Lincoln Electric Company tend to make Lincoln's work force quite stable. Since a stable work force composed of highly productive individuals tends to result in a highly productive organization, individual productivity is also examined. It is concluded that the Lincoln worker has more of his needs satisfied through employment than docs the average industrial worker. In order to satisfy those needs which remain capable of motivating the worker, he must proceed in a manner consistent with the organization's goals. This is the most important explanation advanced for the highly productive nature of this company’s work force. In concluding this study, a discussion of the applicability of this system is presented. It is decided that there is nothing unique in the manufacture of welding equipment which would prevent this plan from succeeding in other industries; however, the environment within which this plan was developed is not typical, and has contributed greatly to its success. / Master of Science

Although the research reported here has not satisfied its primary objective of a mathematical expression of diameter distributions in natural stands of Virginia pine, several constructive conclusions and recommendations are possible. All of them are offered with the perspective that research in the interest of advancing growth and yield techniques in forestry is needed, that the study has been exploratory to begin with, and that the contributions presented here, however conclusive or trivial, are the beginnings of a foundation for further research work. Certain deficiencies in the study are apparent, if not obvious. The major deficiency in the statement of the problem and its conclusion is the lack of a rigorous criterion, or criteria, for judging the success of a fitted distribution. Chi-square was used in this project to test the success of the model, but as the work progressed it became increasingly clear that chi-square was not the best criterion for the purpose of this work. It is the utilitarian purpose of the model that more aptly determines its success, for it is the ability to describe with sufficient precision the attributes of the forest stand that justly determines whether or not the model is useful. Therefore, Validation of the model should be connected with the forester's interest in volume, value, quality, cost estimation, return, profit and any other attributes useful in management of timber. / Master of Science

The single-phase rectifier filter circuits, including the half- and full-wave rectifiers with a capacitor and full-wave rectification with either a series inductor or a choke-input filter, have been analyzed taking into account the voltage drop across the tube and the transformer. In these analyses the high-vacuum thermionic diode was considered. The voltage-current characteristic curve of a diode was assumed linear, and the equivalent resistance of the tube was chosen equal to the reciprocal of the slope of the diode characteristic curve in the conducting region. For the capacitive filtering case, the equations expressing the ignition angle, the extinction angle, and the ratio of the d-c output voltage to the peak value of the applied voltage when the steady state condition is reached have been derived. It was found that these equations not only depend upon the product of the angular frequency of the applied voltage and the time constant of load circuit, but also depend on the ratio of the load resistance to the equivalent resistance of the tube and the source transformer. Most of these equations appear to be of a transcendental form, the solution of which requires either graphical or trial-and-error method. Both of these require tedious work and are time consuming with hand computations. However it is easily accomplished today by the use of an IBM 7040 computer. The calculated curves showing the variation of the ignition angle, the extinction angle, and the ratio of the d-c output voltage to the peak value of the supply-voltage for half- and full-wave rectifications were plotted with wRC as abcissa for several different values of the ratio of the load resistance to the equivalent resistance of tube and transformer. The equations derived for the direct output voltage of the rectifier circuit with either the series inductor or the choke-input filters show that they depend only on the ratio of the load resistance to the total resistance of the tube, the transformer, and the inductor. All the equations mentioned above had been experimentally verified. It is found that the calculated results checked closely with the experimental data if the equivalent resistances were properly chosen. The effect of circuit parameters on the behavior of rectifier circuits operated with three types of filters have been discussed. It becomes evident that the tube and the transformer resistance of practical circuits appears as an additional parameter which cannot be neglected in t4e analysis of the single-phase rectifier. However, inclusion of this resistance greatly complicates the analysis. The method of analysis presented in this paper may be extended to other types of rectifier circuits. Although the analysis made in this paper did not take into account all of the possible factors which may be involved in the practical circuits, nevertheless the results were presented in convenient form for practical use. / M.S.

In the past 30 years, the emphasis on the human relations aspects of management has greatly increased. As a result, new management theories have been advanced, acclaimed and criticized. The purpose of this empirical study was to determine what effect, if any, the biographical factors of age, education and rank had on managerial attitudes in a particular plant and whether the managerial personnel tended to identify with the assumption of Douglas McGregor's widely publicized managerial theories, known as Theories X and Y. Data for the study were gathered by means of attitude questionnaires which were mailed to randomly selected managerial personnel who represented all levels of plant management. The responses were tabulated and statistically analyzed for significance. Based upon the results of this statistical analysis and prudent logic and inference, certain findings were noted and conclusions drawn. The major finding was that in the plant studied, age, education, and rank were relatively unimportant determinants of managerial attitudes. The principal conclusion drawn was that the nature of the work performed and certain, local economic factors, rather than biographical factors, probably accounted for the particular managerial response patterns. / M.S.

M. S.

The subject treated in this thesis is the conditional distribution of a random variable given that the outcome of an associated random variable lies within a specified interval. This may be considered to be an extension of the classical case in which the outcome of the associated random variable is known to assume a specific numerical value. The primary purpose of the study was to examine the properties of a system formed by interval conditioning under the assumption of a suitable linear model. No attention was given to appropriate estimation procedures. The principal conclusions of the study follow. Let X and Y be jointly distributed random variables such that E(Y|X) = α + βX, where α and β are constants, and such that the variance of Y given X is independent of X. Then E(Y|X∈ I) = α + β E(X|X∈ I) and the variance of Y given X∈ I is equal to the variance of Y given X plus β² times the variance of X in its truncated distribution, i.e. truncated in the conditioning interval I. It was shown that the limiting cases of the system. led to the classical conditional results as the conditioning interval degenerates to a point, and to the classical marginal results as the interval expands to encompass the real line. These results were generalized into the case where a random variable Y is conditioned on a set of associated variables, {X_i}^p_i=1, such that X_i∈ I_i, i = 1, 2, … p. Higher conditional moments were found in general. Since third and higher conditional moments are usually functions of the conditioned variables, only an analytic form was given. Consideration was given to the case in which a vector of random variables is to be predicted given that an associated vector of random variables lies in a specified rectangular region. Two types of conditioning were considered simultaneously at this point, namely, the case in which part of the associated variables are conditioned to points and the remainder to intervals. In various places in the body of the thesis and in the appendix consideration was given to the conditions under which the variance of a truncated random variable increases monotonically with the interval of truncation. This was found to be a complicated problem, but necessary and sufficient conditions for this property were developed in the appendix. / M.S.

符艷菁. / "2001年6月" / 論文 (哲學碩士)--香港中文大學, 2001. / 參考文獻 (leaves 172-179) / 附中英文摘要. / "2001 nian 6 yue" / Fu Yanjing. / Lun wen (zhe xue shuo shi)--Xianggang Zhong wen da xue, 2001. / Can kao wen xian (leaves 172-179) / Fu Zhong Ying wen zhai yao. / 論文摘要 --- p.i-iii / Chapter 第一章 --- 緒論 --- p.1 / Chapter 第一節 --- 自由主義在中國 --- p.1 / Chapter 第二節 --- 自由主義知識份子的類別 --- p.8 / Chapter 第三節 --- 文章內容簡介 --- p.11 / Chapter 第四節 --- 儲安平硏究回顧 --- p.14 / Chapter 第五節 --- 小結 --- p.25 / Chapter 第二章 --- 儲安平的自由主義思想 --- p.27 / Chapter 第一節 --- 儲安平生平簡介 --- p.27 / Chapter 第二節 --- 儲安平的自由主義思想根源 --- p.29 / Chapter 第三節 --- 小結 --- p.40 / Chapter 第三章 --- 國民黨統治大陸時期-儲安平與《觀察》 --- p.43 / Chapter 第一節 --- 《觀察》始末 --- p.43 / Chapter 第二節 --- 儲安平的《觀察》政論 --- p.57 / Chapter 第三節 --- 小結 --- p.78 / Chapter 第四章 --- 共產黨統治大陸時期一儲安平與「黨天下」 --- p.83 / Chapter 第一節 --- 1948年至1949年的儲安平 --- p.83 / Chapter 第二節 --- 1949年至1957年的儲安平 --- p.86 / Chapter 第三節 --- 儲安平與「黨天下」 --- p.98 / Chapter 第四節 --- 中共與自由主義知識份子 --- p.132 / Chapter 第五節 --- 小結 --- p.146 / Chapter 第五章 --- 結論 --- p.149 / 附錄 --- p.155 / 附錄一儲安平年譜 --- p.155 / 附錄二《觀察》撰稿人簡況 --- p.166 / 附錄三《觀察》封面 --- p.170 / 附錄四復刊後的《觀察》封面 --- p.171 / 參考資料 --- p.172

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