Synthesis, characterization and electrical properties of N-([4-(aminophenylethynyl)toluene]-N’-(cinnamoyl)thiourea (AECT) as single molecular conductive film

The exploitation of mixed moieties of conjugated acetylide and thiourea system as molecular wire candidates surprisingly unexplored in this distinctive area although the well-known rigid π-systems enhance the electronic field at some extend. Therefore, in the present research, interest has been focused on the design, synthesis, fabrication and evaluation of the performance of a new acetylide-thiourea, N-([4-(aminophenylethynyl)toluene]-N’-(cinnamoyl)thiourea (AECT) based on Donor (D)-π-Acceptor (A) system as an active layer in conductive film. The compounds were successfully characterized via infrared spectroscopy (IR), UV-visible absorption spectroscopy (UV-Vis), CHNS elemental analysis, 1H and 13C nuclear magnetic resonance spectroscopy (NMR), thermogravimetric analysis (TGA) as well as cyclic voltammetry (CV) analysis. The investigation of its potential as dopant system in conductive film was fabricated on ITO substrate prior to the evaluation of its conductivity properties which was carried out by Four Point Probe. The findings from the conductivity analysis showed that the prepared film, AECT/ITO performed better and exhibited increasing conductivity up to 0.2044 Scm-1 under maximum light intensity of 150 Wm-2. This proposed molecular framework gives an ideal indication to act as conductive film and has opened wide potential for application in organic electronic devices

1-(1,3-Benzothia­zol-2-yl)-3-(4-chloro­benzo­yl)thio­urea

The title compound, C15H10ClN3OS2, adopts a cis–trans configuration across the thio­urea C—N bonds with respect to the positions of the benzothia­zole and 4-chloro­benzoyl groups relative to thiono S atom. An intra­molecular N—H⋯O hydrogen bond is present. In the crystal structure, mol­ecules are linked by a weak inter­molecular N—H⋯S hydrogen bond, forming centrosymmetric dimers

Silvicultural prescriptions for second growth forests: a case study in Tekam F.R..

Introduction of mechanized harvesting to inland dipterocarp forest can alter the size, structure, species composition, spatial distribution, stocking level of the pristine rainforest towards a more heterogeneous residual stands. The assessment of second growth forest at landscape level using satellite imagery allows us to examine the variation of stand condition over a large area, and development of a strategic planning to support sustainable management. In developing the silvicultural prescriptions, we looked into three key components of forest stand and used them as the basis to decide on the appropriate silvicultural option. Our assessment approach began with classifying the forest stands into eight commercial species groups. Using a stand projection model we simulated the stand stocking, structure and composition up to 120 years. More than thirty (30) cutting options with minimum dbh limit of 45 cm and 50 cm for non-dipterocarp and dipterocarps, respectively were applied on the simulated stand at each 5 years time step. A growing stock assessment was carried out using minimum stocking standards such as residual stand density, net commercial volume, and proportion of dipterocarps. The silvicultural decision made is not only taking into account the current status of the growing stock but also the projected future stand condition. The paper presents the outcome of the growing stock assessment and recommends silvicultural options to enhance the growing stock of second growth production forest

UV-curable palm oil based-urethane acrylate/clay nanocomposites

Synthesis of palm oil based-urethane acrylate (POBUA) resins was carried out by acrylation of epoxidized palm oil (EPOP) using acrylic acid in the presence of a catalyst and followed by isocyanation to obtain the POBUA. Using the monomer as a diluent in the formulation, 4% of photoinitiator and incorporation of organoclay (1-5% wt), nanocomposites were obtained upon UV irradiation. The X-ray Diffractory XRD study revealed that the nanocomposites obtained were of the exfoliation type. The presence of the clay improved the hardness and did not affect the thermal stability. Similarly, it increased the glass transition temperature Tg but reduced the modulus as the clay content was increased. The improvement of the tensile strength was only obtained when the clay concentration was 5 phr

Assessment on Heck-Immine Derivatives as Organic Semiconductor Materials

This paper reports the synthetic, characterization and theoretical evaluation of new class of hybrid Heck-immine system involving mixed moieties of vinylene (C=C) and azomethines (CH=N) which has been successfully integrated into an addition of organic semiconducting materials. The assessment of 4-[(hexyloxyphenyl)methylene]amino)-4’-chlorostilbene (HEXCS) based on Donor (D)-π-Acceptor (A) was evaluated as active semiconductor material candidates via several spectroscopic and analytical techniques. In turn, the investigation of its potential as dopant system in conductive film was successfully deposited on indium tin oxide (ITO) coated substrate via spin coating method. The relationship between electronic and optical properties, chemical modelling at molecular interactions and electrical performances of the designated system were evaluated. In addition, the quantum mechanical calculation proved that the value of energy separation of HEXCS between HOMO and LUMO exhibits 3.09 eV which was in good agreement with the experimental result of optical band gap 3.10 eV. The findings from the thermal and conductivity analysis revealed that the developed film HEXCS exhibited good stability at high temperature and electrical performance with an increasing conductivity up to 0.1531 Scm-1 under maximum light intensity of 100 Wm-2. Therefore, this proposed type of molecular framework has given an ideal indication to act as semiconductor material candidates potentially use in any designated electronic application

Stocking and species composition of second growth forests in Peninsular Malaysia.

Management of the production forests in Malaysia is currently undergoing a major change as the total extent of undisturbed forest being harvested is diminishing. Currently most of the harvesting operations are being conducted in second growth (rotation) forests and in the near future all production forest will solely consist of only logged forests. This is expected to result in a significant reduction of the supply of raw materials to the industry because second growth forest stands are generally poorer and not so well-stocked with quality timber species. According to the forest management systems applied to these forests, namely the Selective Management System (SMS) and the Malayan Uniform System (MUS), the residual forests should be able to recover in the specified rotation cycle and there should be sufficient quality crop for the second and subsequent harvests. To understand the situation, a study was carried to assess the stocking and species composition of second rotation forests in two production forests located in Tekam Forests Reserve, Pahang and Cherul Forest Reserve, Terengganu. The study results indicated that the second rotation forests are not as productive as predicted but still able to produce an economic harvest in terms of total timber yield within the specified rotation cycle. However, based on inventory projections of existing stocks, it was found that in general the forests have not fully recovered in terms of stocking of commercial species. Species composition has been altered favouring higher dominance of non-dipterocarp species. Some of the major factors that could have contributed to this phenomenon are slower recovery of the forest after the first cut, higher mortality due to logging damage, and implementation of cutting limit prescriptions that favour high removal of dipterocarps as they are dominant in the upper diameter classes. It must be noted that the second growth forest assessed were those that were more than 20 years old. Currently, forest management practices have improved significantly and thus the recent second growth forests are expected to be in a much better condition. The information generated from this project on the status of the stocking and species composition of second growth forest will be essential for improving planning and management of the resource with the aim of enhancing future productivity

Synthesis of radiation curable palm oil-based epoxy acrylate: NMR, FTIR spectroscopic investigations

Over the past few decades, there has been an increasing demand for bio-based polymers and resins in industrial applications, due to their potential lower cost and environmental impact compared with petroleum-based counterparts. The present research concerns the synthesis of epoxidized palm oil acrylate (EPOLA) from an epoxidized palm oil product (EPOP) as environmentally friendly material. EPOP was acrylated by acrylic acid via a ring opening reaction. The kinetics of the acrylation reaction were monitored throughout the reaction course and the acid value of the reaction mixture reached 10 mg KOH/g after 16 h, indicating the consumption of the acrylic acid. The obtained epoxy acrylate was investigated intensively by means of FTIR and NMR spectroscopy, and the results revealed that the ring opening reaction was completed successfully with an acrylation yield about 82%. The UV free radical polymerization of EPOLA was carried out using two types of photoinitiators. The radiation curing behavior was determined by following the conversion of the acrylate groups. The cross-linking density and the hardness of the cured EPOLA films were measured to evaluate the effect of the photoinitiator on the solid film characteristics, besides, the thermal and mechanical properties were also evaluated

The potential of black ant (Dolichoderus sp.) as a biological control agents of the coconut leaf beetle (Brontispa longissima)

The study of coconut leaf beetle infestation, Brontispa longissima on palms and the effectiveness of biological agents as a method of control have been carried out in the laboratory. The study involves the effectiveness of potential black ants as biological agents in controlling beetle populations. The results of laboratory studies on the ability of black ant predation on the B. longissima found that the percentage of mean beetle are eaten by the group that has the number 100 black ants were higher and significantly different (P <0.05) as compared to group numbers 5, 20, 50 and 75 black ants. In addition, black ants also tend to attack and devour the B. longissima larvae and pupa stage compared to adult’s beetle via laboratory studies. It can be concluded that the B. longissima beetle has a great potential for causing considerable damage to the coconut tree which could affect coconut palm industry in Malaysia. However, the usage of biological agents as a control method had shown promising results in order to control the beetle infestation in coconut palm areas

Penetrating large retro-orbital foreign body -fishing sinker: removal via endoscopic transnasal approach

Objective: To report a rare penetrating large orbital foreign body case in a young man with normal vision and ocular movement, and discuss issues regarding best route of its removal. Design: Case report. Materials and Methods: A young man had an accident while fishing and ended up with a sinker penetrated into his right orbit. He has no loss of vision and normal ocular movement. X-ray and CT scan showed a 4 cm bullet shaped sinker in the inferior aspect of the medial wall of the right orbit. Results: The removal was successfully done via endoscopic opening of the posterior ethmoid air cells and creating an opening at the anterior wall of the sphenoid sinus to facilitate the removal transnasally. There was no short term and long term complications resulting from the surgery. Conclusion: Transnasal endoscopic approach should be considered for removal of any medially positioned orbital foreign bodies. This case highlights the importance of a multidisciplinary approach in the management of orbital foreign body and in deciding the best route of foreign body removal to limit potential complications

A Dual Approach on Experimental, Theoretical Insight of Structural Elucidation, Hirshfeld Surface Analysis, Optical and Electrochemical Properties of Acyl Thiourea-Ethynyl Hybrid Derivatives

Hybrid moieties of ethynylated-thiourea, Th1 and Th2 have been synthesised via the addition reaction between ethynyl derivatives and 4-tert-butylbenzoyl isothiocyanate in acetone, and were characterised by selected spectroscopic methods (i.e., 1H and 13C NMR, UV–visible, FT-IR) and elemental analysis. Thermogravimetric analysis indicated that Th1 and Th2 were relatively stable up to ca. 210 °C. Single-crystal X-ray diffraction was used to identify the crystal structure of Th2 in which the centre of 1-acyl thiourea moiety (-C(O)NHC(S)NH) exhibits S conformation. The Hirshfeld surface analysis has allowed visualizing the crystal packing, which is characterised by the prolonged intermolecular N–H⋯O = C and N–H⋯S = C hydrogen-bonding interactions within Th2 molecule. Electrochemical data of both compounds correspondingly exhibit irreversible redox potential processes. Besides, frontier molecular orbitals and Natural Bond Orbital population analysis were computed at the B3LYP/6-31G (d, p) level of approximation, suggesting strong delocalization of the electronic density through a conjugated π-system involving the ethynyl-phenyl and thiourea groups. Graphical Abstract: Figure of molecular structure for acyl thiourea-ethynyl derivative. Two derivatives of acyl thiourea-ethynyl were synthesised and characterised by selected spectroscopic methods such as 1H and 13C NMR, UV-visible, FT-IR, elemental, thermal, electrochemical, X-ray diffraction, and density functional theory (DFT) calculation for molecular orbitals and natural bond orbital population analysis.Fil: Daud, Adibah Izzati. Universiti Malaysia Perlis; Malasia. Universiti Malaysia Terengganu; MalasiaFil: Khairul, Wan M.. Universiti Malaysia Terengganu; MalasiaFil: Arshad, Suhana. Universiti Sains Malaysia; MalasiaFil: Razak, Ibrahim Abdul. Universiti Sains Malaysia; MalasiaFil: Nossa González, Diana Lisseth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Erben, Mauricio Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentin