Assembly Line Balancing by Zero-One Integer Programming

In this study we will present an improved version of the Bowman-White zero-one integer programming formulation of an assembly line balancing problem. We will demonstrate that in solving the above problem, certain steps in Geoffrion's 0-1 integer programming algorithm can be simplified or eliminated. Computational results are given which indicate that the proposed algorithm is faster than the present exact methods.     

机器人登陆月球建造建筑——轮廓工艺的潜力

美国南加利福尼亚大学的比洛克·霍什内维斯(Behrokh Khoshnevis)教授发明的轮廓工艺(contour crafting)是一种由数字控制的建造工艺,通过分层制造技术,可以直接按照计算机模型制造部件。由于无需使用传统混凝土施工中的模板,轮廓工艺可以大大降低成本和建造时间。通过机器人进行建造,最大限度地减少了劳动力的消耗,使该技术凸显巨大的潜力,尤其是在相对危险的环境中,比如充满对人体极具损害的高度辐射的月球。目前,由美国宇航局资助的研究正在探索使用轮廓工艺在月球上建造建筑的潜力,建造所需材料来自月球表面丰厚的风化层。本文对该项研究进行介绍,并对在月球上使用轮廓工艺的优势进行评估。     

Evaluation of plant oils for suppression of crown rot disease and improvement of shelf life of banana (Musa spp. AAA subgroup,cv. Robusta)

Fourteen plant oils were evaluated to control the crown rot disease caused by Lasiodiplodia theobromae and Colletotrichum musae. Five of these, viz. Ocimum sanctum, Cymbopogan citratus, C. martinii, C. nardus and Pelargonium graveolens oils completely arrested the mycelial growth of both test pathogens at their lowest concentration compared to other oils. Besides, these plant oils have also inhibited the activity of cellulolytic and pectinolytic enzymes produced by these pathogens effectively under in vitro condition. The treatment of banana fruit var. Robusta (Cavendish‐AAA) with oils of O. sanctum, C. citratus, C. nardus and C. martinii not only reduced the crown rot severity significantly, but also increased the shelf life of banana fruits. However, under low‐temperature storage (14 °C) condition, O. sanctum oil increased the shelf life of banana fruits up to 48 days without affecting their organoleptic properties. Hence, O. sanctum oil could be used as an alternative to chemical fungicides for the management of crown rot disease.     

Synthesis of chloroanilines at a Ti/ceramic TiO2-cathode

Electroreduction of 2-, 3- and 4-chloronitrobenzenes (2-CNB, 3-CNB and 4-CNB) to the corresponding chloroanilines has been carried out under galvanostatic conditions in aqueous H₂SO₄ at a Ti/ceramic TiO₂-cathode. A comparison of the yield and current efficiency (CE) for the amine formation at a Ti/ceramic TiO₂-cathode with that at a copper cathode indicates the electrocatalytic nature of the former electrode. The results on the cyclic voltammetric behaviour of 2-CNB, 3-CNB and 4-CNB at a Ti/ceramic TiO₂-cathode are also reported, and indicate a mechanism involving heterogeneous redox catalysis by Ti⁴⁺/Ti³⁺.