ANALISA PEMAKAIAN BAHAN BAKAR AMPAS TEBU DAN TEMPURUNG KELAPA DENGAN MENGUJI VARIASI RASIO YANG PALING EFISIEN TERHADAP KETEL UAP SEBAGAI BAHAN BAKAR ALTERNATIF

Bahan bakar merupakan segala sesuatu yang dapat dibakar dan menghasilkan panas. Bahan bakar yang terdapat di alam dapat berupa padat, cair, dan gas. Ketel uap sangat berhubungan erat dengan bahan bakar yang digunakannya. Berdasarkan pengalaman dari penelitian yang telah dilakukan sebelumnya, bahan bakar biomassa dari limbah tanaman dapat dijadikan sebagai bahan bakar alternative yang ketersediannya dapat terus dijaga dan menghasilkan nilai kalor yang tidak kalah tinggi serta biaya yang cukup terjangkau. Salah satu pabrik yang mengaplikasikannya adalah Pabrik Gula Sei Semayang yang menggunakan ampas tebu dan fiber (cangkang dan serabut sawit) sebagai bahan bakarnya dan menghasilkan efisiensi sebesar 66%. Tujuan penelitian ini adalah mendapatkan nilai efisiensi tertinggi dan terendah serta mendapatkan variasi rasio yang paling efisien digunakan. Penulis melakukan pengujian dan menganalisa campuran ampas tebu (AT) terhadap tempurung kelapa (TK) dengan berbagai variasi rasio menggunakan cara metode tidak langsung, yakni 90% AT : 10% TK, 80% AT : 20% TK, 70% AT : 30% TK, 60% AT : 40% TK, dan 50% AT : 50% TK. Dari hasil pengujian, direkomendasikan rasio bahan bakar yang paling efisien digunakan pada ketel uap merk Yoshieme Japan, dengan suhu uap 325°C, kapasitas uap 60 T/jam, dan tekanan 29 kg/cm2 adalah 90% AT : 10% TK dengan efisiensi sebesar 78,75%

Substrate and cofactor binding interaction studies of galactitol -1- Phosphate 5- Dehydrogenase from Peptoclostridium difficile

Tagatose is a high value low calorie sweetener that is used as a sugar substitute in the food and pharmaceutical industry. The production of tagatose requires the conversion of galactitol-1-phosphate to tagatose-6-phosphate by galactitol-1-phosphate 5-dehydrogenase (PdGPDH). Theobjective of this work is to study the protein-ligand interaction between PdGPDH and its ligands; galactitol-1-phosphate, Zn2+ and NAD+. Understanding of this mechanism will provide an insight into the possible catalytic events in these domains, thus providing information for potential protein engineering to improve the tagatose production. A 3D model of PdGPDH was constructed to identify the catalytic and coenzyme binding domains. In order to understand the interaction of PdGPDH with its ligands, a docking analysis of PdGPDH-substrate, PdGPDH-Zn2+ and PdGPDH-NAD+ complex was performed using CDOCKER in Discovery Studio 4.0 (DS 4.0). A series of docking events were performed to find the most stable binding interaction for the enzyme and its ligands. This study found that Cys 37, His 58, Glu 59, Glu 142 residues from PdGPDH form an active site pocket similar to known GPDH. A catalytic Zn2+ binding domain and a cofactor NAD+binding domain with strong hydrogen bonding contacts with the substrate and the cofactor were identified. The binding pockets of the enzyme for galactitol-1-phosphate, NAD+ and Zn2+has been defined. The stability of PdGPDH with its ligand was verified by utilizing the molecular dynamic simulation of docked complex. The results from this study will assist future mutagenesis study and enzyme modification work to improve the tagatose production

Cellobiohydrolase B of Aspergillus niger over-expressed in Pichia pastoris stimulates hydrolysis of oil palm empty fruit bunches

Background. Aspergillus niger, along with many other lignocellulolytic fungi, has been widely used as a commercial workhorse for cellulase production. A fungal cellulase system generally includes three major classes of enzymes i.e.,β-glucosidases, endoglucanases and cellobiohydrolases. Cellobiohydrolases (CBH) are vital to the degradation of crystalline cellulose present in lignocellulosic biomass. However, A. niger naturally secretes low levels of CBH. Hence, recombinant production of A. niger CBH is desirable to increase CBH production yield and also to allow biochemical characterisation of the recombinant CBH from A. niger. Methods. In this study, the gene encoding a cellobiohydrolase B (cbhB) from A. niger ATCC 10574 was cloned and expressed in the methylotrophic yeast Pichia pastoris X-33. The recombinant CBHB was purified and characterised to study its biochemical and kinetic characteristics. To evaluate the potential of CBHB in assisting biomass conversion, CBHB was supplemented into a commercial cellulase preparation (Cellic ® CTec2) and was used to hydrolyse oil palm empty fruit bunch (OPEFB), one of the most abundant lignocellulosic waste from the palm oil industry. To attain maximum saccharification, enzyme loadings were optimised by response surface methodology and the optimum point was validated experimentally. Hydrolysed OPEFB samples were analysed using attenuated total reflectance FTIR spectroscopy (ATR-FTIR) to screen for any compositional changes upon enzymatic treatment. Results. Recombinant CBHB was over-expressed as a hyperglycosylated protein attached to N-glycans. CBHB was enzymatically active towards soluble substrates such as 4-methylumbelliferylβ-D-cellobioside (MUC), p-nitrophenyl-cellobioside (pNPC) and p-nitrophenyl-cellobiotrioside (pNPG3) but was not active towards crystalline substrates like Avicel ® and Sigmacell cellulose. Characterisation of purified CBHB using MUC as the model substrate revealed that optimum catalysis occurred at 50 °C and pH 4 but the enzyme was stable between pH 3 to 10 and 30 to 80 °C. Although CBHB on its own was unable to digest crystalline substrates, supplementation of CBHB (0.37%) with Cellic ® CTec2 (30%) increased saccharification of OPEFB by 27%. Compositional analyses of the treated OPEFB samples revealed that CBHB supplementation reduced peak intensities of both crystalline cellulose Iα and Iβ in the treated OPEFB samples. Discussion. Since CBHB alone was inactive against crystalline cellulose these data suggested that it might work synergistically with other components of Cellic R CTec2. CBHB supplements were desirable as they further increased hydrolysis of OPEFB when the performance of Cellic® CTec2 was theoretically capped at an enzyme loading of 34% in this study. Hence, A. niger CBHB was identified as a potential supplementary enzyme for the enzymatic hydrolysis of OPEFB

Quantum Control of Spin Qubits Using Nanomagnets

Single-qubit gates are essential components of a universal quantum computer. Without selective addressing of individual qubits, scalable implementation of quantum algorithms is not possible. When the qubits are discrete points or regions on a lattice, the selective addressing of magnetic spin qubits at the nanoscale remains a challenge due to the difficulty of localizing and confining a classical divergence-free field to a small volume of space. Herein we propose a new technique for addressing spin qubits using voltage-control of nanoscale magnetism, exemplified by the use of voltage control of magnetic anisotropy (VCMA). We show that by tuning the frequency of the nanomagnet's electric field drive to the Larmor frequency of the spins confined to a nanoscale volume, and by modulating the phase of the drive, single-qubit quantum gates with fidelities approaching those for fault-tolerant quantum computing can be implemented. Such single-qubit gate operations have the advantage of remarkable energy efficiency, requiring only tens of femto-Joules per gate operation, and lossless, purely magnetic field control (no E-field over the target volume). Their physical realization is also straightforward using existing foundry manufacturing techniques.Comment: 10 pages, 6 figure

Knee joint impedance hybrid modeling and control of Functional Electrical Stimulation (FES)-cyclingfor paraplegic: free swinging trajectory

Functional electrical stimulation (FES) has been used to restore the function of paralyzed muscles due to spinal cord injury (SCI). FES induced movement control is a significantly challenging area due to complexity and non�linearity of musculoskeletal system. A crucial issue of FES is the control of motor function by the artificial activation of paralyzed muscles due to the various characteristics of the underlying physiological/biomechanical system. Muscle response characteristics are nonlinear and time-varying with fatigue issues. In this approach only the quadriceps muscle is stimulated to perform the trajectory motion. This paper presents the initial development of control strategies using FLC and GA in order to optimize the system by FES�cycling trajectory control via Analog Digital Converter,ADC

Knee JointImpedanceHybrid Modeling and Control of Functional Electrical Stimulation (FES)-Cyclingfor Paraplegic: Free Swinging trajectory

Functional electrical stimulation (FES) has been used to restore the function of paralyzed muscles due to spinal cord injury (SCI). FES induced movement control is a significantly challenging area due to complexity and non�linearity of musculoskeletal system. A crucial issue of FES is the control of motor function by the artificial activation of paralyzed muscles due to the various characteristics of the underlying physiological/biomechanical system. Muscle response characteristics are nonlinear and time-varying with fatigue issues. In this approach only the quadriceps muscle is stimulated to perform the trajectory motion. This paper presents the initial development of control strategies using FLC and GA in order to optimize the system by FES�cycling trajectory control via Analog Digital Converter,ADC

The Glaciozyma antarctica genome reveals an array of systems that provide sustained responses towards temperature variations in a persistently cold habitat

Extremely low temperatures present various challenges to life that include ice formation and effects on metabolic capacity. Psyhcrophilic microorganisms typically have an array of mechanisms to enable survival in cold temperatures. In this study, we sequenced and analysed the genome of a psychrophilic yeast isolated in the Antarctic region, Glaciozyma antarctica. The genome annotation identified 7857 protein coding sequences. From the genome sequence analysis we were able to identify genes that encoded for proteins known to be associated with cold survival, in addition to annotating genes that are unique to G. antarctica. For genes that are known to be involved in cold adaptation such as anti-freeze proteins (AFPs), our gene expression analysis revealed that they were differentially transcribed over time and in response to different temperatures. This indicated the presence of an array of adaptation systems that can respond to a changing but persistent cold environment. We were also able to validate the activity of all the AFPs annotated where the recombinant AFPs demonstrated anti-freeze capacity. This work is an important foundation for further collective exploration into psychrophilic microbiology where among other potential, the genes unique to this species may represent a pool of novel mechanisms for cold survival

Meeting the stakeholder needs and sustaining business through sustainability risk management practices: A case study of Malaysian environmentally sensitive companies

Sustainability issues such as climate change, carbon emissions, and energy consumption have become increasingly important issues among business organisations, academics and policy makers. Considering this complexity, stakeholders currently demanding companies to have a sound risk management that are aligned to their interest. Sustaining business requires a strong foundational on the economic, environmental and social aspects to address risks and capture value. Sustainability risk management (SRM) is a process that systematically integrates environmental, social, and economic aspects to address emerging risks and other non-quantifiable risk for company survival. This study aims to examine the impact of SRM practices on the company survival among the environmentally sensitive companies in Malaysia. A case study was carried out to examine the SRM implementation among the environmentally sensitive companies. The finding shows that leadership and compliance are considered as important factors in implementing SRM programme. Other factors such as sound risk culture, adequate risk management tools, and effective business continuity planning are crucial to support SRM implementation. Overall findings revealthat the companies are at the early stage implementing SRM programme and denote there is much room for improvement in the risk management process to create long-term value creation for the stakeholders. This study provides empirical evidence on the significance of SRM factors to the company survival. Given the huge environmental and social costs arising from sustainability issues, companies should intensify their effort to fully implement SRM programme across the organisation to sustain longer

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised