Parametric sensitivity of chain polymerization reactors exhibiting the trommsdorff effect

The recently developed mathematical technique for studying the parametric sensitivity of reactors is extended to include chain polymerization systems exhibiting the gel and glass effects, as well as physical property variations. The sensitivities of the two temperature maxima with respect to various parameters are computed. It is found that, for a sample system, poly(methyl methacrylate), all the sensitivities of the gel effect induced temperature peak attain their maxima at the same conditions—this leads to a generalized temperature sensitivity constraint applicable to reactor design or operation. This sensitivity boundary is associated with high conversions and high molecular weights. The analysis shows that the dimensionless propagation activation energy, ?_p, and the dimensionless initiation activation energy, ?_d, are the two most important parameters governing the system performance. Sensitivities of the gel effect-induced number average chain length peak with respect to various parameters are also obtained. Again, all of these chain length sensitivities show maxima at the same condition, leading to the concept of a generalized chain length sensitivity criterion of constraint. Most importantly, the temperature and chain length sensitivity boundaries are virtually identical.     

Heat and mass transfer in fruits and vegetables and measurement of thermal diffusivity

An experimental apparatus was designed to verify the method of measurement of thermal diffusivity of food produce proposed by the authors in an earlier paper [1]. Also, measurements were done for the time-temperature variation during transient cooling of food produce, and the temperature variation has been calculated by many methods available in the literature. It has been found that the calculation procedure proposed by the authors earlier [2] yielded consistently improved results.     

Fine needle aspiration biopsy of extramedullary leukemia

OBJECTIVE: To study the cytologic features and role of fine needle aspiration biopsy (FNAB) in the diagnosis of extramedullary leukemia. STUDY DESIGN: Forty-one cases of extramedullary leukemia diagnosed by FNAB were analyzed along with their detailed clinical and hematologic features. RESULTS: Common sites of leukemic involvement were lymph nodes (34), skin (4), orbit (1), eyelid (1) and breast (1). The most common variety of leukemia was chronic myeloid in the chronic phase (17). Twenty-six patients were referred to the cytology clinic for FNAB as the initial screening test. In the majority of fresh cases, leukemia was not the first possibility considered, and FNAB played an important diagnostic role. No gross discrepancy was noted in any of the cases. CONCLUSION: FNAB is helpful in the diagnosis of extramedullary involvement by leukemia because of the good morphologic detail of blasts and other granulocytic cells. However, for more accurate subclassification of a hematologic disorder, other hematologic investigations are mandatory.     

Influence of inherent strain on the curie temperature of rare earth ion-doped bismuth vanadate

X-ray line broadening is found to be an effective parameter to estimate the strain associated with rare earth ion (Gd³⁺)-doped polycrystalline bismuth vanadate(Bi₂VO_5·5). The strain increases with increasing Gd³⁺ concentration. It is anisotropic and found to be maximum in (111) plane. The Curie temperature which is known to decrease with increase in the rare earth ion concentration in these compounds is correlated with increase in strain.     

In Vitro Evaluation of Albumin Microspheres Containing Actinomycin D

Albumin microspheres containing actinomycin D were prepared by the heat stabilization method. The compata-bility of the drug with magnetite and the optimum stability of the drug in different pH were studied. Drug loaded albumin microspheres containing magnetite showed good magnetic response. Release of the drug was slow and continued for 7 days exhibiting sustained release property. The difference as regards to the size, shape, drug content and release rate from freshly prepared and freeze dried drug loaded albumin microspheres was negligible.     

预测准确与否需要事实证明

欢迎进入硕果累累的一年--这是根据调查分析家们提供的数据所作的判断.2004年,半导体市场的增长率远远超过其13%左右的平均值.对2004年最乐观的预测如下:Future Horizons公司估计增长25.0%;VLSI Research公司估计增长24.5%;IC Insights公司估计增长23.0%;Gartner Dataquest公司估计增长21.1%;WSTS公司估计增长18.5%.     

哈姆雷特、朱丽叶与电子产品设计师

《罗密欧与朱丽叶》是一出悲剧。假如剧中主角不是罗密欧，换成哈姆雷特，那么该剧会是喜剧还是悲剧?剧情多少会这样发展：这个沉思的丹麦人哈姆雷特爱上了朱丽叶。他用辞藻美丽的独自表达他的爱情永恒。为了爱情，他向友人和占垦家讨教。他意识到没有朱丽叶就无法活下去时、便请求他的家族允许自己向朱丽叶表达爱情。因为家庭仇恨，他父亲命令他马上结束这段恋情。