Setting targets with interval data envelopment analysis models via wang method

Data envelopment analysis (DEA) is a mathematical programming for evaluating the relative efficiency of decision making units (DMUs). The first DEA model (CCR model) assumed for exact data, later some authors introduced the applications of DEA which the data was imprecise. In imprecise data envelopment analysis (IDEA) the data can be ordinal, interval and fuzzy. Data envelopment analysis also can be used for the future programming of organizations and the response of the different policies, which is related to the target setting and resource allocation. The existing target model that conveys performance based targets in line with the policy making scenarios was defined for exact data. In this paper we improved the model for imprecise data such as fuzzy, ordinal and interval data. To deal with imprecise data we first established an interval DEA model. We used one of the methods to convert fuzzy and ordinal data into the interval data. A numerical experiment is used to illustrate the application to our interval model

Directional Slack-Based Measure for the Inverse Data Envelopment Analysis

A novel technique has been introduced in this research which lends its basis to the Directional Slack-Based Measure for the inverse Data Envelopment Analysis. In practice, the current research endeavors to elucidate the inverse directional slack-based measure model within a new production possibility set. On one occasion, there is a modification imposed on the output (input) quantities of an efficient decision making unit. In detail, the efficient decision making unit in this method was omitted from the present production possibility set but substituted by the considered efficient decision making unit while its input and output quantities were subsequently modified. The efficiency score of the entire DMUs will be retained in this approach. Also, there would be an improvement in the efficiency score. The proposed approach was investigated in this study with reference to a resource allocation problem. It is possible to simultaneously consider any upsurges (declines) of certain outputs associated with the efficient decision making unit. The significance of the represented model is accentuated by presenting numerical examples

Ocean thermal energy conversion: the promise of a clean future

Due to the world’s heavy dependence on fossil fuels for electricity, pollution and global warming is on the rise. However, numerous countries are still relying on diesel generators as their main source of energy. There is a lack of practical alternative energy source that can meet the global energy demand without posing any threat to the natural environment. Ocean Thermal Energy Conversion (OTEC) is a concept that has the potential to address this growing issue. It is basically a mechanism that exploits the temperature difference between warm surface seawater and cold deep ocean water, to produce electricity. Although OTEC has a low energy density, the thermal energy in the ocean is vastly abundant. OTEC development has been dormant for a long time since it was first proposed in 1881. However, it has now regained recognition worldwide as a realistic solution to our world energy issue. Instead of having a great potential for power generation, it also carries the ability to produce high value products from the large volume of Deep Sea Water (DSW) that can be released as by-products of OTEC plant operation. These products can hold a very profitable place in industries such as pharmaceutical, food, cosmetics and mineral water production. Further research on ocean current and DSW properties can someday lead to the commercial used of OTEC. This paper is a review of the basic concept, present status and future prospects of OTEC around the world

Thermal properties of PLA/kenaf green nanocomposite: Effect of chemi-mechanical treatment

This study was conducted to produce green composite from kenaf with better thermal properties. Kenaf fibre was successfully prepared by chemi-mechanical method. Kenaf fibre was firstly treated with sodium hydroxide (NaOH) at 6% w/w followed by acidic treatment with different concentrations (0.5M, 1.0M and 1.5M). The PLA/kenaf nanofibre composites were referred as KC0.5, KC1.0 and KC1.5 according to acid concentration used. Differential scanning calorimetry (DSC) was done to investigate thermal properties of the composites. The glass transition, crystallization and melting temperature shows similar trend where 1.0M treated fibre composites gives better thermal properties than 0.5M and 1.5M treated fibre composites. Transmission electron microscopy (TEM) micrographs suggested the nanofibre dispersion in mixed-pattern; exfoliation and small agglomeration

Thermal Properties of PLA/Kenaf Green Nanocomposite: Effect of Chemi-Mechanical Treatment

This study was conducted to produce green composite from kenaf with better thermal properties. Kenaf fibre was successfully prepared by chemi-mechanical method. Kenaf fibre was firstly treated with sodium hydroxide (NaOH) at 6% w/w followed by acidic treatment with different concentrations (0.5M, 1.0M and 1.5M). The PLA/kenaf nanofibre composites were referred as KC0.5, KC1.0 and KC1.5 according to acid concentration used. Differential scanning calorimetry (DSC) was done to investigate thermal properties of the composites. The glass transition, crystallization and melting temperature shows similar trend where 1.0M treated fibre composites gives better thermal properties than 0.5M and 1.5M treated fibre composites. Transmission electron microscopy (TEM) micrographs suggested the nanofibre dispersion in mixed-pattern; exfoliation and small agglomeration

Utilization of Bivalve Shell-Treated Zea mays L. (maize) Husk Leaf as a Low-Cost Biosorbent for Enhanced Adsorption of Malachite Green

In this work, two low-cost wastes, bivalve shell (BS) and Zea mays L. husk leaf (ZHL), were investigated to adsorb malachite green (MG) from aqueous solutions. The ZHL was treated with calcined BS to give the BS-ZHL, and its ability to adsorb MG was compared with untreated ZHL, calcined BS and Ca(OH)2-treated ZHL under several different conditions: pH (2–8), adsorbent dosage (0.25–2.5 g L1), contact time (10–30 min), initial MG concentration (10–200 mg L1) and temperature (303–323 K). The equilibrium studies indicated that the experimental data were in agreement with the Langmuir isotherm model. The use of 2.5 g L1 BS-ZHL resulted in the nearly complete removal of 200 mg L1 of MG with a maximum adsorption capacity of 81.5 mg g1 after 30 min of contact time at pH 6 and 323 K. The results indicated that the BS-ZHL can be used to effectively remove MG from aqueous media