bluuebunny/crossref_metadata_2025 huggingface dataset:
A Conceptual Framework to determine Medical Equipment Maintenance in Hospital Using RCM Method
Authors: Salim Siti Hajar , Mazlan Saiful Amri , Salim Siti Aisyah
Published: February 2019

Maintenance services are performed to ensure the equipment is operating according to manufacturer standard and maintained at a desired level of quality. The implementation of maintenance services may prevent unexpected breakdown and disruption of operations in a hospital. However, there were numbers of cases reported on the frequent breakdown of medical equipment even though the maintenance program is in place and practised. Therefore, the reliability of the maintenance services was questioned especially when the breakdowns occurred after the maintenance services being performed. This paper proposes a conceptual framework to determine the accurate maintenance program for medical equipment in the hospital using Reliability Centred Maintenance (RCM) method. The recommendation from the RCM will assist to identify the root cause of the breakdown and minimize the number of breakdown for medical equipment in the hospital. RCM process is known as one of the most effective maintenance approaches to reduce the number of maintenance activities and hence minimizing the cost of maintenance incurred.
Determination of Direct to Indirect Accident Cost Ratio for Railway Construction Project
Authors: Nik Mohd Ainul Azman Nik Nur Khairunnisa , Che Ahmad Asmalia , Mohd Derus Mohmad , Mohd Kamar Izatul Farrita
Published: February 2019

Construction industry involves dangerous activities which few are exposed to a high risk of being fatal, injuries and damages to machinery and property. The construction of Mass Rapid Transit (MRT) and Light Rail Transit (LRT) have no exception to those accidents. The accident can bring economic burden to project stakeholders especially contractors and client. However, the accident cost is relatively complicated because of its “hidden” or “invisible” portion. Thus, this paper is aimed to determine the ratio of direct to indirect accident cost for railway construction projects. The study was conducted using self-administered questionnaire distributed to safety practitioners (n=11) at MRT and LRT construction projects. A total of 36 out of 43 reportable accident cases successfully collected for the study and were analysed with simple descriptive statistics. The findings show that the accident cost ratio for fatality is 1:1.22, permanent disability is 1:1.94, and temporary disability is 1:1.19. The overall accident ratio for all accident classifications is 1:1.23. The findings of the current study may impact future safety cost estimation process in determining the hidden accident costs for railway construction projects.
Gap Analysis between ERP procedures and Construction procedures
Authors: Hewavitharana F.S.T. , Perera A.A.D.A.J.
Published: February 2019

Although Enterprise Resource Planning (ERP) offers many benefits to the construction industry, construction companies still hesitate to adopt ERP systems. This may be due to long-term practiced ad-hoc behaviors in the construction industry, which do not match with the standard procedures embedded in ERP systems. Therefore, through this research, it is expected to evaluate the gap between construction procedures and ERP procedures technically. Hence, to obtain indicative data for the study, a questionnaire was designed and distributed to selected 210 individuals among contractors, subcontractors, and clients in the Sri-Lankan construction industry who have used ERP. In total, 174 completed questionnaires were returned and then statistically analyzed using Chi-Square test with the Mini tab tool. It is concluded that there is a significant gap between the construction procedures and ERP procedures in identified fields related to the construction industry. The highest significant gap exists in the field of Inventory management with Chi-Square 158.766 > 9.48. And HRM (142.366), Asset Management (130.264), Finance Management (126.267), Site Operation (103.793), Project management (53.88), Purchases (34.324), Petty cash (28.337), Estimating and Tendering (22.148), Sub-Contractor management (0.492) respectively. Ultimately with the identified gaps, a framework was established to meet the organizational processes and ERP processes.
Risk Disclosure and Performance of Malaysian Construction Public Listed Companies
Authors: Ching Ching Wong , Alashwal Ali M. , Azli Mohd Rahim Faizul
Published: February 2019

Due to regulatory reforms, corporate governance has evolved with Enterprise Risk Management become prominence since the 1990s. In Malaysia, Statement of Risk Management and Internal Control with Malaysian Corporate Code of Governance are regulatory compliance on risk management for the Public Listed Companies. Companies are required to make risk disclosures in their annual report based on Risk Management Framework, which indirectly provided insights for shareholders and investors to assess the company’s performance. This study aims to determine the extent of risk implementation based on Risk Management Framework and the effect on construction Public Listed Companies performance. The sample of this study consists of 227 construction Public Listed Companies in Malaysia Bourse from 2011, 2014, 2015, 2016 and 2017. Content analysis is conducted on the company’s annual reports for the five years based on Risk Management Framework components and financial ratios. The study revealed the presence of both guidelines had increased risk disclosure among construction Public Listed Companies but there was no significant improvement in their financial performance.
Implementation of Technology Transfer in Mass Rapid Transport (MRT) Project in Malaysia
Authors: Omar Roshartini , Hua Tan Khai , Sallehuddin Aina Mardia , Sarpin Norliana , Yahya Mohd Yamani , Chen Goh Kai , Mohamed Sulzakimin , Masrom Md Asrul Nasid
Published: February 2019

Technology transfer is a useful resource for improving technology and it is widely used in various industrial fields. The application of technology transfer in the construction industry can be viewed via the Mass Rapid Transit (MRT). The transfer of technology has been implemented in the construction of the MRT but there are a number of factors and barriers in implementing as well. Therefore, this study attempts to understand the technology transfer in the MRT project in the country and study the factors that influence the process of technology transfer in the MRT project. Data collection was conducted through interviews with respondents involved in technology transfer MRT project namely MRT Corporation Sdn. Bhd. And MMC-Gamuda KVMRT (PDP) Sdn. Bhd. The results showed organisational capabilities, relational capabilities, communications, level of absorptive capacity and technological capabilities, development of skilled human resources and economic advancement are factors that influenced the transfer of technology in MRT project. The findings of this study can be used as a guide for the MRT project in the future to avoid failure in the technology transfer.
Warm Mix Asphalt Additive in Natural Rubber Modified Bitumen
Authors: Mustafa Kamal Mazlina , Hadithon Kamarul Arifin , Abu Bakar Rohani
Published: February 2019

The growing concern over the reduction of emissions and energy savings has led to the development of new paving technologies that are environmentally friendly. As a result, a warm mix asphalt technologies have been introduced to reduce the mixing and compaction temperature for asphalt mixture. The influence of additive with variation loading on the performance of Natural Rubber Modified Bitumen was acquired. In this work, Brookfield rotational viscometer test and Dynamic Shear Rheometer (DSR) mechanical analysis method and typical bitumen tests were employed. Results indicated that viscosity and the penetration of the Natural Rubber Modified Bitumen decreased, while the softening point increased with addition of additive. This in return would possible to reduce mixing and compaction temperature of the Natural Rubber Modified Mixture. Findings of the study also showed that the additive resulted in increase in complex shear modulus value and the rutting parameter modulus.
Contractual Aspects in the Utilisation of Level Two Building Information Modelling (BIM) within Malaysian Public Construction Projects
Authors: Kamal Hasni Mohamad Izani Ahmad , Ismail Zulhabri , Hashim Norfashiha
Published: February 2019

Building Information Modelling (BIM) is a technology and process that are transforming way of designing, constructing, operating and using the building or facility. In essence, BIM models is a platform for collaboration as it encourages intensive communication and interdependence among multidisciplinary project members. In Malaysia’s BIM Guide, this collaborative process can be seen in Level 2 BIM Maturity which all designers engaged in projects work together to create a single computer-generated 3D Model. From this process, many benefits that BIM promises such as clash free construction, quality of design and greater certainty could be achieved. Therefore, the Malaysian Government announced the implementation of at least 40% of Level 2 BIM for public projects costing RM100 million and above in 2019. However, despite mutual understanding between construction players, the full integration of BIM in the project lifecycle seems to be a daunting task. In the context of the Malaysian Public Sector, many uncertainties could arise pertaining to legal and contractual matters i.e. whether or not the existing contractual instruments are able to support the collaborative environment and digital information sharing that Level 2 BIM engenders. This paper presents a narrative review of published literature on the concept of Level 2 BIM and contractual consideration based on the utilisation of BIM within Malaysian Public construction projects, which includes books, government publications, conference presentation slides, newspaper articles and paper-based journal articles. This paper concludes that in order to legitimise multidisciplinary collaboration and integration of information in BIM within existing standard forms of contract, the development of a contract protocol and suitable procurement model are necessary.
What is BIM? A Need for A Unique BIM Definition
Authors: Doan Dat Tien , Ghaffarianhoseini Ali , Naismith Nicola , Zhang Tongrui , Rehman Attiq Ur , Tookey John , Ghaffarianhoseini Amirhosein
Published: February 2019

Building Information Modelling (BIM) has rapidly developed in the construction industry recently; it is also considered as one of the core concepts in the Industry 4.0. However, BIM understanding is always seen as a significant problem for BIM implementation. Therefore, this paper aims to provide the insights into BIM awareness of the construction practitioners with the focus on the BIM definition in the New Zealand construction industry where BIM is still in its early stages. 22 interviews were conducted with 26 construction experts holding important positions in their companies and having at least eight years’ experience in the industry. The results indicated that BIM has a variety of meanings to the interviewees. Four different definitions including Building Information Model, Building Information Modelling, Building Information Management, and Software/Technology were identified which was considered inappropriate, the fallacies of definition, for the construction industry. Also, most of the construction practitioners are seen as not well-aware of BIM, especially the SMEs. Furthermore, the results also indicated that the BIM survey potentially provided a false result at least regarding the BIM adoption rate in the New Zealand construction industry, which urges the BIM survey host to clarify the BIM definition before conducting the survey. The results of this paper are hoped to alarm the government and construction organizations to have a unique BIM definition for BIM development in New Zealand to ensure the consistent understanding among the industry.
Exploring Types of Waste Generated: A Study of Construction Industry of Pakistan
Authors: Akhund Muhammad Akram , Memon Aftab Hameed , Memon Nafees Ahmed , Ali Tauha Hussain , khoso Ali Raza
Published: February 2019

The construction sector is responsible for providing fundamental physical structure required for living and survival of human life. Increased development works have led in resulting the massive amount of waste generation in developing countries. Due to poor management system on sites, it has become more crucial and exerts several negative impacts on society and the environment. This Unused waste material has a negative impact on the ecosystem and needs a considerable amount of money for recycling, reusing and disposal of the waste. Like other developing countries Pakistan is spending a significant portion of its GDP on handling construction waste. Among the several other factors, the key contributes are highlighted in this study. This study is exploratory work investigating the types of construction waste generated on site and their relative impact of the project cost in construction projects of Pakistan. Through questionnaire the opinion of clients, consultant and constructor have been taken to identify the major types of waste having more impacts on cost and time. Through Average index, severity index and importance index, the probability of occurrence of waste through different materials, severity level of waste production by these materials, and the overall effect of all waste generating materials have been found respectively. Among the materials sand, concrete, tile is the most common materials, which are responsible for a waste generation while time and cost are the two most common non-physical waste generating factors.
Assessment of Modern Architecture in the Living City of UAE: Incorporating Sustainable Design into Covered Bazaar Buildings
Authors: El Amrousi Mohamed , AbdulHafiz Feda Isam
Published: February 2019

In the UAE modern architecture is now considered part of early attempt of sustainable design and heritage of the living city that reflects good design practices, especially after the establishment of the Urban Planning Council and Estidama Guidelines. Madinat Zayed Gold Souk/bazaar still attracts many visitors because it represents a space of specialization, tt is also a representative of ‘modernism’ of 1970s Parallel examples such as the Central Market/Gold bazaar in Sharjah also manifest architectural attempts to create architecture within cultural and environmental contexts. Traditional wind towers known as Barjeel, vaults, domes and arcades borrowed from the broader spectrum of Islamic arts, recreated in concrete act as architectural containers of heritage and spaces of socio-cultural interaction accessible to all social groups. The aim of this research is to examine modern Arab ornament and its application on buildings in the downtowns of Abu Dhabi and Sharjah. This research examines the environmental properties of the gold bazaars in Abu Dhabi and Sharjah using Formit architectural modelling software. This study outlines the importance of forms of representation of form and identity in rapidly developing Arab cities and proposes a number of solutions/designs to improve the facades, and to enhance the comfort in the building then offers scenarios to make these buildings more sustainable.
Microclimate Model for Urban Heat Island Simulation: A Prediction Tool Extension to Calculate the Ambient Temperature of Building
Authors: Mohd Zinal Nur Atikah , Amir Amnorzahira , Manap Norpadzlihatun
Published: February 2019

Universiti Tun Hussein Onn Malaysia (UTHM) is a public university located at Parit Raja, Batu Pahat, which is categorized as a suburban area of Johor, Malaysia and is still in development progress. However, the quick pace of development leads to changing of land use from green surface to hard surface building blocks which tends to increase the temperature level and reduce outdoor comfort level of occupants in UTHM. In addition, the available software simulations that used currently for temperature monitoring is mostly too complicated for educated non-scientist such as urban planners and architects. This research objectives are to predict the ambient building temperature of reference area by using Screening Tool for Estate Environment Evaluation software (STEVE) and to provide comparison for both of field measurements with STEVE results. In order to achieve these objectives, a total of six stations considering different urban morphologies are evaluated to give a better understanding on implication of urban heat island. The daily minimum (Tmin), average (Tavg) and maximum (Tmax) air temperature for six stations in UTHM have been developed and validated based on a long-term field measurement. The pavement (PAVE), building (BDG), green plot area ratio (GnPR), average height area (AvgHT), sky view factor (SVF), total wall area (WALL) and result of the temperature (Tmax, Tminand Tavg) are automatically calculated by STEVE from the developed 3D models. The results show that the percentage different of temperature between STEVE and field measurement is in a range of 0.9-1.0% and this has strongly indicated that STEVE is suitable to be used as temperature prediction tool.
Moringa-functionalized rice husk ash adsorbent for the removal of amoxicillin in aqueous solution
Authors: Oliva Maria Patrichia , Corral Clinton , Jesoro Michael , Barajas John Raymond
Published: February 2019

Lack of stringent policies requiring water treatment facilities to combat occurrence of residual antibiotics in effluents critically impairs the resiliency of low-income communities to drug-resistant pathogens. In an attempt to mitigate the effects of residual drugs in aqueous media, we investigate the extent to which rice husk ash (RHA) functionalized by Moringaoleifera protein (MOP) sequestrates amoxicillin in solution. A semi-factorial design was implemented to evaluate the influence of initial amoxicillin concentration, initial MOP functionalized RHA dosage, and contact time on the removal on amoxicillin in water. Results of our experiments have shown that MOP functionalization enhanced RHA by doubling its rate to sequestrate amoxicillin molecules in solution. This strongly indicated that MOP adhered on the surface of RHA significantly improved its capacity to remove amoxicillin contamination in aqueous solution. Statistical analysis employed further supported our results by implying a significant difference between the performance of MOP-functionalized and bare RHA. In conclusion, our results strongly suggest that MOP functionalization can be a potential practical solution to alleviate the vulnerability of communities to emerging antibiotic pollution.
Bioleaching kinetics of trace metals from coal ash using Pseudomonas spp.
Authors: Pangayao Denvert , Promentilla Michael Angelo , Gallardo Susan , van Hullebusch Eric
Published: February 2019

The kinetics of bioleaching of chromium, copper, manganese and zinc from coal ash using Pseudomonas spp. isolated from coal ash pond was investigated. From the previous study, parameters used for bioleaching were 1% pulp density, 90 rpm, 37°C and 5 ml inoculum was placed in a 100 ml fresh medium with the ash. These conditions were used for bioleaching of coal ash for 30 days. Moreover, the initial pH of the solution is 8.20 and decreases to 8.61. After 30 days of bioleaching, the maximum metal leached were 13.77% Cr, 14.61% Cu, 6.33% Mn and 12.18% Zn. Assuming that the coal ash will shrink uniformly with respect to time using Shrinking Core Model, the kinetic data showed linear plot for percent metal leached versus time, suggested that diffusion through ash layer control was the rate controlling mechanism.
A systematic molecular design framework for an environmentally benign solvent recovery process
Authors: Ooi Jecksin , Ng Denny K. S. , Chemmangattuvalappil Nishanth
Published: February 2019

Computer Aided Molecular Design (CAMD) techniques have been extensively applied to design solvents for different applications. Most of the CAMD problems only aim at generating solvents that meet the predefined functionality. Nevertheless, it is important to consider the effect of solvent on the safety, health and environmental impacts during the recovery process. This paper presents a single stage CAMD framework that simultaneously quantifies the environmental impact of the solvent recovery process. The environmental impact of the process can be estimated through IChemE Sustainability Metrics. Besides, molecular properties that have an impact on the quantitative evaluation of the environmental impact of solvent recovery process are included in this framework. Weighted sum method coupled with Fuzzy Analytic Hierarchy Process (FAHP) weighting approach is employed to solve the multi-objective molecular design framework. A case study on solvent design for residual oil extraction from palm pressed fiber is presented to illustrate the proposed framework. In this work, only energy balance around multistage evaporator is incorporated into CAMD formulation as energy required to recover the solvent contributes to the largest portion of the whole process. The results show that the designed solvents simultaneously possess target functionalities and reduce the environmental impact of solvent recovery process.
Ethylene glycol injection for hydrate formation prevention in deepwater gas pipelines
Authors: Adisasmito Sanggono , Parubak Enos
Published: February 2019

The presence of hydrates in deepwater oil-gas-field operations is a fairly frequent issue. It is very important to have a hydrate management strategy for normal operation and while shutdown. The objectives of the work were to mitigate the hydrate formation in the deepwater operation conditions. This study analyzed the sensitivity of the hydrate compound formation process in flow line system with diameter 9.5" with a length of about 22 Km in deep water gas-field, based on actual condition and production rate assumption. Based on the simulation results for the actual production flow rate, hydrate is formed at a distance of about 17991 ft from the wellhead that is in the first segment of the well head to the Pipeline End Manifold (PLEM). For a higher production flow rate, hydrate formation occurs at a distance approaching the wellhead which is part of the first segment. This is because the temperature at the bottom of the deep-water is as low as 40 °F. The addition of MEG to prevent the formation of hydrate compounds was further investigated. Fluid flow modeling was performed under steady state with CH4 levels of about 87%, pressure of 1900 psia, 125 °F temperature and 85 MMSCFD production flow rate as the basic conditions. The data used in this research is taken from one of the deepsea gas field in Makassar Strait. Adding MEG dose of 0.175% mole, lowering the hydrate-forming temperature from 67.8 °F to 3.2 °F. Similarly, for increasing MEG doses, the greater the decrease in hydrate formation temperature. The addition of MEG dose of 0.175% mole at each production flow rate gives different working fluid temperature with hydrate formation temperature of 5.5 °F to 18 °F, so it is safe from the risk of hydrate formation.
Improved process modifications of aqueous ammonia-based CO2 capture system
Authors: Obek Christine Ann , Ayittey Foster Kofi , Saptoro Agus
Published: February 2019

Extensive research works on CO2 capture process using MEA have been carried out and showed promising results. Nevertheless, it has been acknowledged that the use of MEA is associated with high cost, solvent degradation issues and corrosion. The issues above have motivated researchers to explore and test other potential solvents such as aqueous ammonia (NH3). As result, NH3 based CO2 capture systems have recently attracted much attention as an alternative to MEA based counterparts. Despite their encouraging applications, high volatility of NH3 raise concerns on the energy requirement related to the solvent recovery. Consequently, energy efficient NH3 based CO2 capture systems by modifying the process is desirable. This study, therefore, aims to propose and evaluate three different stand-alone process configurations of absorption-desorption processes in a NH3-based system and compare them with the traditional absorption-desorption system in respect to total energy consumption. These modifications include Rich Solvent Split (RSS), Lean Vapor Compression (LVC), and Rich Vapor Compression (RVC). Results indicate that among these three proposed process modifications, LVC led to the highest reboiler energy savings of 38.3% and total energy savings of 34.5% compared to NH3 based conventional configuration. These findings can serve as essential recommendations for further studies on and large-scale implementations of aqueous NH3 as a better solvent.
A P-graph model for the synthesis of tri-generation systems for multi-period operation
Authors: Gonzales Veronica , Aviso Kathleen , Tan Raymond
Published: February 2019

The progressive development of renewable energy technologies is attributed to the growing energy demand and the depletion of non-renewable resources. Renewable energy technologies are usually characterized by intermittent availability of resources, affecting the capability of energy systems to meet projected energy demands. Tri-generation, or the simultaneous generation of three energy types, becomes a potential solution wherein integration of renewable energy technologies is used to maximize resource efficiency. Synthesizing these systems will require the consideration of techno-economic data and the use of computer-aided techniques to facilitate optimization and design. Mixed-Integer Linear Programming is a commonly used technique for Process Network Synthesis, but its application to complex problems becomes problematic due to numerous alternatives and parameter variations. The Process graph framework offers a less laborious option with its unambiguous representation of process systems, utilizing three algorithms in generating all combinatorially feasible solutions that present the user with both optimal and near-optimal solutions. These become helpful in decision-making especially when factors such as those impossible to be captured mathematically need to be considered. This work presents a P-graph model developed for the synthesis and design of multi-period, biomass-fired, tri-generation systems with a case study for power generation in the Philippines to demonstrate its capabilities.
Analysis of the interaction between particles and gliding arc discharge in a spouted bed reactor
Authors: Nakajima Atsushi , Kodama Satoshi , Sekiguchi Hidetoshi
Published: February 2019

In this paper, the interaction between particles and gliding arcs in a spouted bed reactor combined with gliding arc discharge was investigated using a high-speed camera. Based on the images captured by the camera, we evaluated the retention time for gliding arcs, the contact frequency of particles with the gliding arc, and the passage area of the gliding arc until its disappearance. The effects of the gas flow rate; electrode angle, which is same as the cone angle of the spouted bed; and applied voltage of gliding arcs were investigated. The retention time for gliding arcs was extended by a high applied voltage, the passage area was increased at a high gas flow rate, and the contact frequency was increased by decreasing the electrode angle. The results obtained here can support the optimization of particle treatment processes in a spouted bed with gliding arc discharge.
Talisay (Terminalia catappa) seed husk biochar for adsorption of lead (II) ions in artificially contaminated soil
Authors: Canlas Joric John , Go Jenika Cris , Mendoza Ardith Clarisse , Dimaano Maria Natalia
Published: February 2019

Lead, a commonly found heavy metal in contaminated soil, is highly mobilized in acidic conditions resulting to rapid soil leaching. This study investigated the effectiveness of biochar derived from Talisay (Terminalia catappa) seed husks employing the long-term immobilization of Lead in an artificially contaminated soil using simulated acid rain water meant for 100 years of rain with 5% amendment rate. Before immobilization, the heating temperatures were varied at 400, 500 and 600°C to determine its optimal pyrolysis temperature. The biochar was pyrolyzed under three different temperatures: with 1-hour residence time. SEM images revealed that the degree of porosity of the biochar produced increased as the temperature increased. In addition, the biochar produced at 600°C has the highest % fixed carbon and % elemental carbon indicating stability. It then shows that Talisay seed husks are feasible materials for biochar production that can be used for the amendment of lead contaminated soil. The Freundlich and Langmuir models were used to describe the heavy metal sorption equilibrium of the biochar. Results showed that the biochar best fitted the pseudo-second-order models and Langmuir isotherm models and that the biochar displayed a favorable adsorption. Also, the immobilization experiment showed that the soil amended with biochar immobilized Pb decreasing its concentration by 99.47%. Therefore, the produced biochar is suitable for Pb remediation in contaminated soils.
Extraction of cellulose from waste papers for the preparation of cellulose graft-poly (acrylamide) for superabsorbent
Authors: Aquino Chamylle Rose , Carlos Fauline Deune , Padua Francis , Tayactac Honeylet , Zulueta Adrienne Hera , Roque Erison , Almanzor Nuna
Published: February 2019

This article reports the use of wastepaper pulp as a direct source of cellulose for producing superabsorbent polymer. The white papers obtained from the offices in Adamson University were cut into 1 inch square pieces and drenched with distilled water and borax. This procedure was done couple of times to achieve a pH of 8 and consistency of 1%-2%. Commercial cotton was used as control to compare and differentiate the properties and structures with the superabsorbent polymer (SAP). Various trials have shown the value of 60 acrylamide beads to produce SAP with optimum performance. FTIR analysis shows properties that are characteristics of cellulose-based SAP. In the present investigation, the influence of temperature, effect in varying salt concentrations, swelling rate and water retention at constant temperature were evaluated. The SAP’s maximum swelling capacity ranges from 0.6561 g to 1.0638 g regardless of the amount of NaCl used. The swelling rate of the SAP proves that it gets heavier with time. Hence, it can be implied that the ability of the SAP to retain water is good. The temperature dependence data revealed the sorption process was favorable at higher temperature. The SAP will absorb the highest amount of solution at 500C given that the solution is pure.
Process Optimization for the Production of Potassium-Carrageenan Nanofertilizer by Ionic Crosslinking
Authors: Toledo Marivic , Migo Veronica , Alfafara Catalino , Maguyon-Detras Monet Concepcion , Brutas Clint Charles
Published: February 2019

The effects of nutrient loading, mixing temperature, time and type of drying method (freeze and oven drying) on the total K content of the potassium-carrageenan fertilizer formulated through ionic crosslinking was evaluated. Direct effect on the total K was observed at varying nutrient loading at nutrient-to-carrier mass ratios 1:2 and 2:1 with no significant effect at varying mixing conditions and drying. Instead, variations are observed on the qualitative properties of potassium-carrageenan such as viscosity due to the thermoreversible properties of kappa-carrageenan. A linear model based on the significant factor was generated to predict the potassium content at the range of nutrient ratio adjusted to 1:2 to 1.5:1 to obtain a center ratio 1:1, with a maximum predicted value of 26.64% w/w. Potassium and carrageenan crosslinking yield an organized helix structure based on SEM micrograph with crystalline structure. Freeze dried fertilizers yield smaller particle sizes about 300nm due to its easily size reducible physical appearance than in oven-drying where film like particles are observed. Further, a decrease in absorbance is observed at increased potassium concentration. Evaluation of release pattern using buffer system shows slower release of nutrient using carrageenan carrier compared to conventional fertilizer at pH sensitive environment.
Effect of magnetic field on the synthesis of carbon nanotubes using MPECVD
Authors: Lugod Cyril Benedict , Auresenia Joseph
Published: February 2019

CNT production is limited by issues regarding CNT growth and morphology. Due to this, further studies on experimental factors regarding CNT production are needed to optimize CNT production in a commercial scale. This study focuses mainly on the determination of the effects of the presence of a magnetic field during CNT synthesis in a Microwave Enhanced Plasma Chemical Vapor Deposition (MPECVD) process using a Whirlpool AVM585 conventional microwave oven. The study also determined the effects of hydrogen catalyst plasma pretreatment on CNT growth. The experiment was based on a Taguchi orthogonal array design. The effects of the experimental factors such as magnetic field strength (0, 5, and 10 mT), catalyst pretreatment time (10, 15, and 20 min), hydrogen gas flow rate (25, 50, and 75 mL/min), and microwave power (451, 570, and 740 W) on the responses such as the catalyst nanoparticle Feret diameter, CNT diameter, tortuosity, weight, and purity were investigated. Among the design factors, application of magnetic field at 10 mT improved all the responses, most notably the CNT diameter and tortuosity being reduced by 60% and 48% compared to runs with no magnetic field, respectively. Under tortuosity, magnetic field was the design factor which had the greatest effect on decreasing the tortuosity of the CNTs at around 100 times the effect measured under other design factors. Catalyst plasma pretreatment was most optimal at the highest hydrogen flow rate and microwave power setting, under the influence of the highest magnetic field strength. The effects of the factors during catalyst plasma pretreatment also resulted to improved characteristics of the CNTs during the CNT synthesis. Overall, the findings suggest that the application of a magnetic field during catalyst plasma pretreatment and the subsequent CNT synthesis results to catalyst nanoparticles and CNTs with improved properties such as lower catalyst nanoparticle Feret diameter, CNT diameter, tortuosity and higher CNT yield and purity.
The production of biogas from palm oil mill effluent as substrate with variation of agitation speed with fed-batch system
Authors: Aznury Martha , Jaksen  , Hasan Abu , Artindah Ralli
Published: February 2019

The purpose of this research is to determine the effect of variation of agitation speed on biogas production from palm oil mill effluent and cow dung as substrate by using modified digester fed-batch. The addition of agitation in the fermentation tank digester in this research to accelerate the contact between the microorganisms with the substrate so that the process runs more effectively. Thus biogas production with variations of agitation velocity have 90 and 102 rpm. The research is conducted by fed-batch that is the addition of substrate in fermentation tank as much as 1 liter for 2 days which aim to get optimum biogas production result. The results of this research indicate that the speed of agitation affects for biogas production. The optimum biogas production occurred at 102 rpm agitation speed after 30 days fermentation time was 26.5116% mol CH4.
Prediction of acid mine drainage formation and zinc migration in the tailings dam of a closed mine, and possible countermeasures
Authors: Tabelin Carlito , Sasaki Asuka , Igarashi Toshifumi , Tomiyama Shingo , Villacorte-Tabelin Mylah , Ito Mayumi , Hiroyoshi Naoki
Published: February 2019

Acid mine drainage (AMD), the very acidic and highly contaminated leachate generated in closed/abandoned mines, is commonly managed by neutralization to raise the pH and precipitate most of the heavy metals. Although effective, this approach does not generate any product of economic value, so it is very costly and unsustainable in the long-term. Unfortunately, there are currently no effective alternatives to neutralization, and one way to improve the sustainability of this process is to reduce the volume of AMD generated and/or the concentration of heavy metals. The tailings dam investigated in this study is located in northern Hokkaido, Japan. Detailed characterization of borehole core samples showed that even after almost 40 years of exposure to the environment, the tailings still contain pyrite (FeS2) and substantial amounts of copper (Cu) and zinc (Zn). Reactive-transport modeling using Visual MODFLOW predicted that AMD quality would likely continue to deteriorate with time and that treatment should be continued for at least 1,000 years. The model also predicted that a barrier with low permeability installed downstream of the tailings dam or ground sealing techniques for recharge reduction could lower the volume of AMD and concentration of Zn from the site.
Optimization of furfural extraction from Theobrama cacao wastes using response surface methodology
Authors: Uy John Rhen , Careo Neil Dominic , Llarena Dominick , Barajas John Raymond
Published: February 2019

Cacao farming in the Philippines is continually expanding due to an influx of government support and funding. Although a comprehensive development program was implemented, the large volume of cacao biomass waste generated annually remains underutilized. In an attempt to provide a means of reusing this waste, we test the extent to which furfural can be extracted from cacao pod wastes. A box-behnken experimental design was used to obtain the optimal conditions in the acid-catalyzed extraction of crude furfural. Extraction time (min), hydrochloric acid concentration (M), and amount of sodium chloride (g) were found to have a significant influence on the extraction yield of crude furfural. Actual values of these independent variables were chosen on the basis of preliminary experimental results. Optimum conditions using ridge analysis were found to be: extraction time 35.0 min, hydrochloric acid concentration 5.0 M, and amount of sodium chloride 7.0 g. Furfural extraction was also performed at optimum conditions to assess the validity of the empirical model. In conclusion, the high furfural extraction yield obtained in our experiments presents an opportunity to harness these unregulated wastes in producing high quality products.
Catalytic thermal decarboxylation of palm kernel oil basic soap into drop-in fuel
Authors: Neonufa Godlief , Pratiwi Meiti , Prakoso Tirto , Purwadi Ronny , Soerawidjaja Tatang
Published: February 2019

Catalytic thermal decarboxylation of basic soaps derived from palm kernel oil to produce dropin fuel was investigated. The C12/14 and C12/16 methyl ester had been used as the model compounds of this study. The purpose of this study was to produce drop-in fuel, especially jets biofuel, by catalytic thermal decarboxylation of basic soaps from palm kernel oils. In this study, two types of Magnesium-Zinc metal combination were used for preparing the basic soaps, both directly have a role as a catalyst. The reaction was carried out at 370°C and atmospheric pressure for 3 hours in the semi-batch reactor. Approximately 41 and 43 weight% of the yield and selectivity of about 97 and 98% toward the jets biofuel had been obtained in both experiments, respectively. The results showed that decarboxylation of basic soaps of C12/14 and C12/16 methyl ester were converted into drop-in fuel, especially jets biofuel in the relatively good yield of conversion.
Phosphorus recovery from wastewater and sludge
Authors: Damalerio Regina G. , Belo Lawrence P. , Orbecido Aileen H. , Pausta Carla Mae J. , Promentilla Michael Angelo B. , Razon Luis F. , Eusebio Ramon Christian P. , Saroj Devendra , Beltran Arnel B.
Published: February 2019

Wastewater and sludge are potential resource of phosphorus (P) for fertilizer production. One method of recovering phosphorus is via chemical precipitation. In the study, phosphorus was recovered from wastewater and sludge. First, hydrolysis was carried out to release the phosphorus in the sludge by the addition of 1.0M acid (sulfuric acid) or base (sodium hydroxide) solution mixed for three hours at 200 rpm. The hydrolyzed sludge was filtered, and the pH of the solution was adjusted to 9.0. Precipitation for both wastewater and hydrolyzed sludge solution was carried out using magnesium chloride hexahydrate (MgCl2•6H2O) and ammonium chloride (NH4Cl). The mixture was stirred for an hour for crystallization. Precipitates were allowed to settle for 24 hours before it was filtered and dried in an oven at 55-58oC for 24 hours. The dried sample was grinded and characterized using Fourier transform infrared spectroscopy (FTIR), x-ray fluorenscence (XRF), and scanning electron microscope with energy-dispersive x-ray spectroscopy(SEM-EDX).
Production of activated carbon from corn cobs and mango kernels via H3PO4activation and mediated hydrothermal treatment
Authors: Armonio Joaquin Victorino Mari , Caragdag Ivan Joshua , Escorpizo Jaylym Aldryne , Miranda Karizza Mae , Raymundo April Joyce , Roque Erison
Published: February 2019

In this study, the activated carbon produced from mango kernels and corn cobs by impregnating the hydrothermally treated raw materials with 85% H3PO4were characterize for their physical surface morphology and types of surface functional groups using SEM and FT-ir, respectively. Six samples of activated carbon were submerged for 1 hour, the second sample for 2 hours, and the third sample for 3 hours. SEM results showed that both KAC (Kernel Activated Carbon) and CAC (Corn Activated Carbon) had increasing roughness and irregularity along with residence time of the samples. Results from FT-ir (Fourier-transform infrared spectroscopy) testing of the mango kernels samples showed that a C-O stretch, C-H, C=O stretch, and C-N stretch on the surface. While corncobs consist of C-H bend, and O-H bend for the 1-HR sample. The 2-HR and 3-HR samples consist of C-O stretch, C-H wag, C-N stretch. Analysis of the relationship between residence time and adsorptive capacity was done using AAS via batch adsorption in a tri-metal solution of Cu(Copper), Ni(Nickel), and Pb(Lead) with results that showed CAC and KAC, with soaking time of 3 hours is a good adsorbent of Copper and Nickel, while soaking time of 2 hours yields the best adsorption conditions for both CAC and KAC.
Competitive effects for the adsorption of copper, cadmium and lead ions using modified activated carbon from bambo
Authors: Ocreto Jherwin , Go Chester Ian , Chua Jans Cholo , Apacible Cyrrus Jude , Vilando Anabella
Published: February 2019

Modified activated carbon from bamboo was used as a low-cost potential adsorbent to remove cadmium, copper and lead in single, bimetal and trimetal aqueous solutions. Using the initial concentration of 40 ppm, the analysis was conducted to determine the effect of pH (2.5, 3.0, and 5.5), contact time (60, 90, 120 min) and adsorbent dosage (20, 40, 60 mg/50 mL of solution). Results showed that for single metal aqueous solution, the % adsorption for Cu, Cd, and Pb were 89.0%, 87.4%, and 99.5% respectively. For bimetal aqueous solution the % adsorption of CuCd, CuPb, CdCu, CdPb, PbCu,and PbCd were 90.6%, 98.9%, 55.1%, 80.7%, 99.6%, and 96.05%, respectively. While for trimetal aqueous solutions, % adsorption of Cu, Cd, and Pb were 87.4%, 73.0%, and 98.4%, respectively. The % removal uptake followed the order Pb > Cu> Cd gave insights into competition effects among the three solutes during the adsorption process. Using Box–Behnken Design, the effect pH of the aqueous solution is an important controlling parameter in which the % adsorption increased as the pH level is increased while other parameters were insignificant.
Acidity effects of K promoted Co-based catalyst with NH4OH addition of the impregnation solution for Fischer-Tropsch synthesis
Authors: Al Fatony Zaky , Febriani Yosi , Makertihartha IGBN , Gunawan Melia Laniwati , Subagjo
Published: February 2019

Fischer-Tropsch synthesis (FTS) with cobalt-based catalyst has been developed to produce wax as a feedstock for further catalytic cracking. During catalyst preparation, NH4OH was added to the salt nitrate precursor to investigate the influence on catalyst acidity. Catalysts were prepared by the dry impregnation method and characterized by XRD, BET and NH3-TPD analyses. These properties were correlated with activity and selectivity of the catalyst. Activity tests showed CO and H2 conversion were in the range of 36.4% to 80.3% and 34.2% to 74.1% respectively. The cobalt particle size measurements exhibited 7.6-8.5 nm. The presence of weak acid sites on catalyst with large surface area and pore size is mainly responsible for obtaining high yields of C5+ hydrocarbon due to suppression of cracking properties. The product distribution showed a higher selectivity to C5+ in the range of 53.57% to 96.5%. In this study, FTS was evaluated by using fixed-bed reactor at 20 bar, 250 C, and WHSV of 1500 ml/g.cat/h-1.
Production of lactic acid from cellulose using solid catalyst
Authors: Doungsri Sujitra , Rattanaphanee P. , Wongkoblap Aatichat
Published: February 2019

Lactic acid (LA), one of the important biomass derived platform chemicals, has been used in food and chemical industries, especially in biodegradable polymer as polylactic acid (PLA). The aim of this work is to study the one-pot production of LA from cellulose by using different solid catalysts. The reaction was conducted in a high pressure batch reactor and the catalyst used in this study were ZrO2 and Al2O3. The reaction was carried out at temperature of 200oC for 6 hr. and under nitrogen pressure of 1 MP. It was found that the production yield of LA were 8.02% and 6.63%, when the ZrO2 and Al2O3 catalysts were used respectively. The result indicated that the ZrO2 may effect on the LA production because of the acid and base sites of the ZrO2. Therefore, the reaction pathways for conversion of cellulose into lactic acid have been investigated, and developed the new conditions to achieve the higher yield.
Opticien célèbre. Nikolaï Guennadievitch Bassov
Authors: Haidar Riad
Published: February 2019

Physicien et inventeur soviétique, Nikolaï Bassov a effectué d’importants travaux en électronique quantique. Il est surtout connu pour ses travaux pionniers sur les oscillateurs et amplificateurs de rayonnement électromagnétique, qui ont permis le développement du maser et du laser. Il obtient le prix Nobel de physique en 1964, avec son compatriote Aleksandre Mikhaïlovitch Prokhorov et l’Américain Charles H. Townes.
L’OCT en ophtalmologie
Authors: Grieve Kate , Paques Michel
Published: February 2019

Depuis l’invention de l’ophtalmoscope en 1850 par Helmholtz, le domaine de l’imagerie de la rétine a connu encore une grande avancée en 1991 avec l’invention de la tomographie par cohérence optique (optical coherence tomography, OCT) par James Fujimoto au MIT. Cette technique interférométrique a introduit pour la première fois dans l’histoire de l’imagerie de l’oeil la possibilité d'observer les couches cellulaires de la rétine en coupe virtuelle en profondeur de manière non invasive. Depuis cette date l'OCT a continuellement évolué et son champ d'application ne cesse de se développer au point d'être devenu l'examen de première intention dans le domaine des maladies rétiniennes.