Timber Losses during Harvesting in Managed Shorea robusta Forests of Nepal

Logging and sawing of timber using conventional tools by unskilled workers causes enormous damage to the valuable timber, residual stand, regeneration, and forest soil in Nepal. The purpose of this study was to find out the volume reduction factor and identify major strategies to reduce timber losses in the tree harvesting process in the Terai Shorea robusta forest of Nepal. Field measurements and product flow analysis of 51 felled trees from felling coupes and randomly selected 167 sawed logs were examined to study harvesting losses. Responses from 116 forest experts were analyzed to explore strategies for reducing harvesting and processing losses. The results showed that timber losses in the felling and bucking stage with and without stem rot were 23% and 22%, respectively. Similarly, timber losses in the sawing stage with and without stem rot were 31% and 30%, respectively. Paired t-test at 5% level of significance revealed that there was significant loss in both tree felling and log sawing stages with present harvesting practice. The most leading factor contributing to timber loss in all of the three stages was the use of inappropriate equipment during tree harvesting. Use of synthetic ropes for directional felling and skidding as well as flexible and portable sawing machine with size adjustment options during sawing were mainly recommended as strategies to reduce timber losses. This study serves as a baseline study to identify and quantify timber losses in different stages of tree conversion and also formulate their reduction strategies in Nepal.

A note on bi-objective optimization for sustainable supply chain network design in omnichannel

PurposeThis paper aims to correct the existing mixed integer programming (MIP) model proposed by Yadav et al. (2019) [“Bi-objective optimization for sustainable supply chain network design in omnichannel.”, Journal of Manufacturing Technology Management, Vol. 30 No. 6, pp. 972–986].Design/methodology/approachThis paper first presents a counterexample to show that the existing MIP model is incorrect and then proposes an improved mixed integer linear programming (MILP) model for the considered problem. Last, a numerical experiment is conducted to test our improved MILP model.FindingsThis paper demonstrates that the formulations of the facility capacity constraints and the product flow balance constraints in the existing MIP model are incorrect and incomplete. Due to this reason, infeasible solutions could be identified as feasible ones by the existing MIP model. Hence, the optimal solution obtained with the existing MIP model could be infeasible. A counter-example is used to verify our observations. Computational results verify the effectiveness of our improved MILP model.Originality/valueThis paper gives a complete and correct formulation of the facility capacity constraints and the product flow balance constraints, and conducts other improvements on the existing MIP model. The improved MILP model can be easily implemented and would help companies to have more effective distribution networks under the omnichannel environment.

Development of Tools for Thermodynamic Calculation of Rocket Engine Characteristics using the Julia Programming Language

The experience in developing an algorithm and a program for the thermal-chemical calculation of the characteristics of a rocket engine is presented. The program is written in Julia. To calculate the equilibrium composition of combustion products the freely distributed library Ipopt is used. The program is interfaced to the database on thermodynamic properties of individual substances IVTANTERMO. For the convenience of processing, the information on thermodynamic properties is stored in two text files of a special form. The program has been developed using the simplest working process model according to which the flow is one-dimensional, the product flow is adiabatic, there are no friction losses, the product flow is equilibrium, and the speed of condensed particles is equal to the gas flow speed. Ratios for calculating the derivatives of composition, as well as equilibrium values of heat capacity and sound velocity are given. The text of the program can be used in the study process and can easily be adapted to more complex models of the rocket engine workflow. The calculation results obtained using the developed program are in good agreement with the results of TERRA calculations. The execution time of one calculation for a four-element fuel, which includes the determination of the combustion products characteristics in the chamber, the critical cross section and at the nozzle cross section, varies in the range of 3--5 s

Green Initiatives in Supply Chain Management Drives Enterprises’ Competitiveness and Sustainability

The advent of supply chain management (SCM) strategy over the past four decades coupled with innovations in technology has revolutionised management of enterprises tremendously. The SCM strategy has enhanced supplier-customer collaboration and integration in the delivery of product/service to ultimate customers, while the enabling role of technology speeds up the information and product flow. The effectiveness and efficiency emanating from supply chain management is a manifestation of enterprises’ inclusive concern of value-creation from economic, environmental and social attributes, also referred as triple-bottom line (TBL). Such enterprises are streamlined as they utilise resources sparingly and produced less waste. Hence, they are lean, resilient and possess capacity to withstand disruptions. These qualities are derived from green initiatives and render these enterprises’ competitiveness and sustainability. This is change management through which conventional supply chain management transforms into green supply chain management (GSCM) by refocusing value-creation in embracing the triple-bottom line that drives the competiveness and sustainability of enterprises.

Main actors in the Cephalopod Global Trade Network: a graph theory analysis

The global cephalopod trade is a multi-billion-dollar industry that involves fishing and captive breeding of a dozen species of high commercial value. It also contributes wholly or partly to the income and subsistence of thousands of families around the world. Despite its broad ecological, social, and economic importance, limited research has been conducted to describe the scope and scale of the global cephalopod trade. To date, there is no specific regulation, nor have tracking systems been implemented, to study the traceability of the global cephalopod trade at an international level. We provide, for the first time, a comprehensive description of the legal trade in cephalopods to understand who the key world players in the cephalopod seafood markets are. We analysed 20 years of records compiled by the United Nations COMTRADE database. The database contained 115,108 entries for squid and cuttlefish and 71,659 entries for octopus, including the product flow between traders (countries or territories) weighted by volume (kg) and monetary value (USD). Graph theoretic analysis was used to explore the emergent properties of this database through the analysis of different measures of centrality that provide insights on the key role of the traders in the network. Our findings show that most of the market movements between ca. 250 traders are led by three countries (China, Spain, and Japan), involving 11 clusters of traders based on the volume and value of cephalopod trade and number of transactions. The most important cluster, that dominates the cephalopod seafood market, is composed by 5 Asian countries (China, India, Republic of Korea, Thailand, and Vietnam), 2 European countries (the Netherlands and Spain) and the USA. This work identifies the traders that act as major exporters and/or importers, the modulators, intermediaries or accumulators, the best-connected traders, the principal flow routes and the weaknesses of the global cephalopod trade network. This network information is essential to advance towards a transparent and sustainable cephalopods world trade.

Mathematical Modelling of Conveyor-Belt Dryers with Tangential Flow for Food Drying up to Final Moisture Content below the Critical Value

This work presents the mathematical modeling of the conveyor-belt dryer with tangential flow operating in co-current, which has the advantage of improving the preservation of the organoleptic and nutritional qualities of the dried food. On the one hand, it is a more cumbersome dryer than the perforated cross flow belt dryer but, on the other hand, it has a low air temperature in the final section where the product has a low moisture content and, therefore, it is more heat sensitive. The results of the mathematical modeling allowed a series of guidelines to be developed for a rational design of the conveyor-belt dryer with tangential flow for the specific case of the moisture content of the final product XF lower than the critical one XC (XF < XC). In fact, this work follows a precedent in which a mathematical model was developed through the differentiation of the drying rate equation along the dryer belt with the hypothesis that the final moisture content XF of the product was higher than the critical one XC. The relationships between the extensive quantities (air flow rate and product flow rate), the intensive quantities (temperatures, moisture content and enthalpies) and the dimensional ones (length and width of the belt) were then obtained. Finally, based on these relationships, the rules for an optimized design for XF < XC were obtained.

THE ANALYSIS OF WASTE ACTIVITIES IN SUPRAMAK BED PRODUCTION BY USING VALUE STREAM MAPPING AND VALSAT APPROACHES

X Ltd. is a company which is producing hospital equipment with one of its products is supramak bed (patient’s bed). From the observation at the production floor of X Ltd, several non-value added activities are identified, which are components accumulation, reworking a number of products which do not meet the standards, idling operators, and waiting in working process. Based on the results of VSM Current State Map is obtained that total time for value added activities are 96816 seconds and for non-value added activities are 80869 seconds. Based on WAM analysis, the highest waste occurs during waiting time with an index of 19.09%. Based on VALSAT analysis, the proposed input from researchers are as follows: giving the mandates to the warehouse department, monitoring product flow, creating and enforcing SOP, increasing the number of forklifts, and analyzing transportation effectiveness

STUDI PRODUK HALAL DAGING AYAM POTONG DENGAN PENDEKATAN RANTAI PASOK (SUPPLY CHAIN) DI MAKASSAR

Supply Chain is a concept and regulatory system related to product flow, information flow and financial flows. Activities in the supply chain for broilers consist of the process of raising chicken products by breeders, then processing them into chicken meat that is ready to be marketed from breeders to consumers. The purpose of this study was to analyze the supply chain for chicken meat products and to determine the availability of chickens in the Chicken Slaughterhouse and the availability of chickens in the city of Makassar. Data collection methods are carried out by observation and interviews. Data processing with the preparation of problems in a hierarchy, Validity and Reliability Examiners, Supply chain mapping and hierarchical determination, Calculation of the actual value of each matrix, Inserting weights into the decision matrix, Calculating the normalization value . Data analysis that has been collected is then processed using the Supply Chain Operations Reference (SCOR) method. Of the 15 sub-districts in Makassar city, there are 4 sub-districts which are slaughter centers namely Tamalate (97,643), Manggala (100,762), Biringkanaya (999,554) and Tamalanrea (88,895). where 3 districts are directly adjacent to the buffer area for chicken products, namely Maros and Gowa. The potential supply of chickens to Makassar city will be even greater along with the demand for chicken meat protein. The conclusion is the supply chain channel for chicken products with 3 alternatives, starting from livestock producers, collecting traders, retailers, consumers, then the second alternative is starting from producers, collecting traders and consumers. And the third alternative is starting from the cage, basket, slaughterhouse and consumers.