Search

In this research article, a leftover of Cymbopogon flexuosus stem (CFS) collected from the oil extraction industry was examined for its ability as a reinforcing agent in a polymer composite. Anatomical, morphological, physical, chemical, mechanical, and thermal characteristics of the CFS fiber were examined. Chemical analysis revealed the presence of higher amount of cellulose (68.13%), which offers better bonding properties and higher tensile strength (431.19 ± 23.96 MPa). Moreover, the density of the fiber (1270 kg/m3) found using physical analysis was less than that of synthetic fibers, which paves a path in replacing hazardous synthetic fiber. Solid-state nuclear magnetic resonance and Fourier transform infrared spectrum spectroscopy analyses were conducted to study the functional groups of the extracted CFS fiber. The thermal stability (253.17°C), activation energy (73.01 kJ/mol), and maximum degradation temperature (345.08°C) were investigated by thermogravimetric analysis. X-ray diffraction analysis confirmed the semi-crystalline nature of the fiber with crystallinity index (46.02%) and crystallite size (13.96 nm). The CFS had a smooth surface, as conformed by an atomic force microscopy and scanning electron microscope analysis. Altogether, this study highlights the feasibility of leftover CFS fiber residue as reinforcement in biopolymer matrices replacing synthetic fiber.

This research is mainly focused on the impact of bio waste filler in mechanical applications. The bio wastes from banana, pineapple and coconut plants were used for preparing Banana Fly Ash (BFA), Pineapple Fly Ash (PFA) and Coir Fly Ash (CFA) fillers. These fillers (1–4 wt. %) were incorporated with 30 wt. % of Sisal (S)/Pineapple (P) hybrid fiber composites using epoxy matrix. The X-Ray Diffraction (XRD) results proved the presence of quartz as the main element in the fly ash powders. Tensile strength of 23.78–33.79 MPa was observed by the substitution of BFA, PFA and CFA filler powders, compared to hybrid natural fiber composites with 20.45 MPa properties. Filler mixing add to the adhesion between fiber/matrix and increases the mechanical properties. Similarly, flexural and impact properties enhanced up to 22.11%, 21.77%, with filler incorporation. The SEM results explains good bonding nature by the application of filler powders. The EDX results proved the presence of silica and other inorganic content in the polymer composites adding to the properties.

Dry sliding friction and wear behavior, hardness, and thermogravimetric analysis (TGA) of Cissus quadrangularis stem fiber (CQSF)/epoxy resin composite, reinforced with red mud particulate filler w...

In this article, mechanical and tribological characterization of Cissus quadrangularis stem fiber (CQSF)/epoxy resin particulate with and without coconut shell ash (CSA) powder was carried out. The materials were fabricated by the hand lay-up method. Epoxy and 30 wt.% CQSF with 40 mm fiber length were taken to fabricate the base material, and CSA was separately added at 2.5, 5, 7.5, and 10 wt.%. In this way, five materials were fabricated for mechanical and tribological investigation. The tribological characterization was analyzed by Response Surface Methodology (RSM) using Design-Expert software, and pin-on-disc wear testing machine was used to calculate the specific wear rate of the materials under different experimental conditions. A design table was created for four factors and three levels using full factorial central composite design. The maximum tensile (110.31 MPa) and flexural (136.11 MPa) strength obtained at 5 wt.% CSA addition and after that reduced. The maximum hardness (98 HRRW) and impact strength (20.03 J/cm2) were obtained at 10 wt.% CSA particulate-filled CQSF/epoxy composite. CQSF/epoxy with 5.9 wt.% CSA filler yielded better specific wear rate (6.67 × 10−5 mm3/Nm) compared with other compositions, which was found in the RSM technique. Scanning electron microscopy (SEM) images were taken to identify failure mechanisms for the specimen.

A novel epoxy-based composites were fabricated by reinforcing pineapple/flax (PF) fibers and peanut oil cake (PCF) filler using the hand layup cum compression moulding technique and investigated its mechanical, water absorption and wear properties as a function of wt.% of PF fibers (20–40 wt.%) and PCF (1–3 wt.%). The XRD and FTIR results proved the presence of lignocellulosic nature in PCF. Mechanical test results showed significant enhancement in the properties after the addition of PCF. The maximum tensile, flexural and impact properties of 37. 89 MPa, 70.28 MPa and 96.99 J/m were observed in the composites having 20 wt.% of PF and 2 wt.% of PCF. Taguchi based optimization observed a lower specific wear rate (SWR) with 2 wt.% PCF/20 wt.% PF/5 N load and 1500 m sliding distance (SD) combination. The ANOVA results proved the significance of PCF, PF fiber, sliding distance, and load for SWR in this experimentation. The Taguchi optimized results observed a lower coefficient of friction (COF) in 2 wt.% PCF/20 wt.% PF/5N load/500 m SD combination. SEM results displayed surface deformations in the wear-tested composites.

The purpose of this present research work is to assess the static and dynamic mechanical properties of an eco-friendly natural cellulosic fiber (Phoenix sp.) reinforced epoxy composites. The cellulosic fiber was isolated from Phoenix sp. plant petioles, and it was treated with various concentrations of sodium hydroxide (5, 10, 15 and 20%) solution. The impact of treatments on tensile, flexural, impact and dynamic mechanical properties of the fabricated composite was explored and optimized. Moreover, the mechanically tested samples were subjected to morphological analysis to predict the failure mechanisms. The outcomes revealed that the treated fibers had good interfacial bonding with epoxy matrix (confirmed through morphological and single fiber pull-out studies), reduced the failure mechanisms (fiber pull-outs and fiber debonding) and exhibited good static and dynamic mechanical properties of composite materials than untreated fiber composites. It is concluded that composites fabricated using 15% of sodium hydroxide treated fiber could be used to manufacture automotive panels and other lightweight industrial products.

This research work focuses on the wear characteristics of hybrid composites prepared using Sisal fiber (SF) /Pineapple fiber (PF) and Pineapple fly ash (PA) in various wt.%. Linear reciprocating tr...

The foremost intention of this work is to test the suitability of the Ficus religiosa Root Fiber (FRRF) as the better reinforcement for the natural fiber-reinforced composite structures. In the current work, the attempts have been made with the view of improving the physical, thermal, chemical, surface, and crystalline properties of FRRF employing 5 wt% of NaOH solution. Five samples of FRRF have been prepared by soaking the raw fiber in the alkali solution under different soaking times. The thermogravimetric analysis results reveal that the alkali-treated FRRF soaked for 60 min holds a maximum range of thermal stability (improved by 9.54%); in turn, the remaining analyses have been carried out with that fiber samples. The increased quantity of cellulose contents was witnessed over the surface of treated FRRF. The improvement in the CI from 42.92–48.64% was noted as the result of X-Ray Diffraction test. The morphology study results ensured that the surface of the treated FRRF became so rough comparably, which confirms the removal of unwanted wax and impurities on the fiber surface. All the above observations validated that the proposed fiber is suitable to prepare the composite structures after the optimal alkali treatment.

This investigation is aimed to analyze the effect of sodium hydroxide (NaOH) treatment on the physical, chemical, structural, thermal and surface topography of Phaseolus vulgaris fibers (PVFs). The...

Scenarios focus on the practical behavior of anaerobic decomposition systems to enhance biogas production, in addition to assure economic progression and ecological sustainability. The present study has framed to identify the potential hydrolytic bacteria from five different sources since principally the efficacy of hydrolytic bacteria determines the rate of hydrolysis of anaerobic decomposition and thereby biogas production. Among the 40 dominant bacteria isolated from diverse bases, 10 isolates were selected as efficient through preliminary screening. Consequently, the premier enzyme activity obtained from the isolate G5 obtained from goat rumen fluid for cellulase (44.16±1.00 U/ml), protease (260.63±1.35 U/ml) and lipase (33.20 ± 0.81 U/ml). Morphological, biochemical and molecular characterization revealed that G5 is Bacillus sp. DDG5 (KM093856.1). A range of pH (7.0-7.5) and temperature (40oC) was sufficient for the highest activity of hydrolytic enzymes experienced. Biogas production using cow dung showed an improved efficiency of 9.54 % in Bacillus sp. DDG5 treated tank (70.16 ± 1.54 %) in contrast to control (58.13 ± 1.02%) at 30th day. However, this study established that Bacillus sp. DDG5 obtained from goat rumen fluid is the promising hydrolytic bacteria, since it can be applied for proficient hydrolysis of various organic materials to enhance methane production in outlook. Int. J. Appl. Sci. Biotechnol. Vol 6(4): 386-396

Currently, plant fibers, acquired from several resources, have been used widely for numerous applications by textile and green composite industries. The highlights of natural fibers include bio-degradable, uninterrupted source, easy and safe handling. The usage of enzymes in the textile industry fosters the development of eco-friendly technologies in fiber processing and tactics to improve the final product quality. The natural fiber from the stem of Cissus quadrangularis was extracted using an amylase enzyme. In light of these aspects, this work investigated the influence of enzyme usage on the extraction of natural fibers from the surface of C. quadrangularis stem through various characterization methods. The characterization of C. quadrangularis stem fibers (CQSFs) by Fourier transform-infrared spectroscopy, X-ray diffraction and thermogravimetric analysis were conducted. The surface morphology of the normal and fractured samples was studied using scanning electron microscopy.

Flours and starches extracted from the tropical tubers underwent freeze-drying and cooking in comparison with fresh cooking. Freeze-dried and cooked starch (FDS) granules were found to have different shapes and collapsed arrangement whereas freshly cooked starch (FCS) granules had the least varied structures. The freeze-dried flours had larger structures compared to freshly cooked flours. The physicochemical parameters were high in Dioscorea esculenta (DE)-FDS, followed by Amorphophallus paeoniifolius (AP)-FDS and other samples whereas D. alata (DA)-FCS had the lowest, whereas flours followed similar trend. FDS (42.1%) had the highest solubility index and swelling power whereas FCS (11.1%) showed the lowest. The syneresis and light transmittance levels were higher in FDS and FDF. The freeze dried flour and starch showed higher onset (T0), peak (TP), and conclusion (TC) temperature than fresh cooked samples. The variations in IR spectra, thermal properties, and crystalline index were termed as differential function of physicochemical characteristics, structural changes that resulted from freeze drying, and cooking treatment employed.

In recent years, the textile market is proposed to have new types of fibers and yarns. The expansion of eco-friendly fabrics with organic, bio-degradable, and environmentally friendly nature is the current trend to reduce the carbon footprints as well as a carcinogenic effect caused by various synthetic materials. Ecofriendly fabrics possess natural characteristics that are user-friendly, cost-effective, and less harmful nature. The market demand for such fabrics is increasing with the consciousness of the consumer. Bamboo textiles provide a remarkable opportunity for developing sustainable and socio-economically significant textiles in the future. This chapter describes the fabrication and characterization methods for bamboo-based textiles and their futuristic prospects in the textile and apparel industries.

The exploration and utilization of natural eco-friendly materials with high performance, biodegradability and renewability is a need of the hour, in the aspect of diminishing the detrimental effects of synthetic materials and thereby to pledge a sustainable tomorrow. The application of bamboo-based materials expanded largely worldwide due to its significant properties over conventional materials as bio-degradable, recyclable, sustainable, luxurious, and environmentally friendly benefits that maintains the ecological standards. This chapter principally deals with the bamboo geographical distribution, bamboo production, anatomy, bamboo clum properties, bamboo fiber extraction techniques, fiber characterization and the adorability of bamboo fiber as a potential natural reinforcement material for bio-composites and its application in various sectors.

Grewia damine is a flowering plant found in India and Sri Lanka. The fiber taken out from the stem bark of G. damine is found to be novel and selected for characterization study. The G. damine stem bark fiber (GDSF) has rich in cellulose contents (57.78 ± 3.56%). Its lower density (1.378 ± 0.036 g/cm3) makes it fit for use in lightweight applications. The weight percentage values of the chemical constituents confirm the use of GDSF for structural applications. Crystallinity index of GDSF was noted as 30.35%. The mechanical properties of GDSF were predicted as 375.6 ± 16.58 MPa tensile strength and 126.2 ± 11.93 GPa modulus of elasticity. The morphological and atomic force microscopy study results revealed that the fiber has rough surface even in its raw form. Hence it can be used to prepare composite specimens with better bonding strength between fiber and polymer. The thermal stability of GDSF was noted as 326 °C. Weibull distribution plots were drawn for validating the physical and tensile property values of GDSF.

Increase in biological and ecological concern has made to find new natural fibers which are biodegradable, from renewable sources and flexibility to chemical modification. Naturally woven Coconut leaf sheath (CLS) fabric were investigated. Removal of impurities on alkali treatment was carried to check the performance of these CLS fabric. On alkali treatment tensile and thermal properties were enhanced due to increase in crystallinity. The eco-friendly coconut leaf sheath fabric was found to be a suitable reinforcement material in composite structure for biocomposite applications.

Health and sustainability are the major concerns that drive researchers to find novel materials to replace artificial hazardous materials. In this investigation, the mechanical properties of Cissus quadrangularis Stem Fiber (CQSF) reinforced with unsaturated polyester composite were optimized by varying the fiber length and content. To substantiate the findings, chemical property, thermal property, microstructure, and water absorption property were analyzed. Progressive enhancement of mechanical properties was observed with increasing the fiber content and fiber length up to 30 wt.% and 40 mm. However, beyond that limit, there was a decline in the strength due to improper bonding of fiber with matrix. Optimal values of mechanical property for CQSF composite were obtained at 30 wt.% fiber content and 40 mm fiber length, which are comparable with that of common artificial fiber-reinforced polymer composites.

Environmental degradation and its effects on human health due to unprecedented use of synthetic fibers, have been heavily felt by the fabricating workers and by the common people in general. The search to develop high-performance materials using environmental friendly natural fibers, is to be encouraged and needs comprehensive characterization. In this paper, discarded and polluting agro waste from food processing industry, known as Tamarind Fruit Fiber (TFF) is tested for its potentiality as a reinforcement in polymer composite. The extracted fibers are subjected to anatomical, physical, mechanical, morphological, thermal and chemical examination. The low density (1.27 g/cm3) provides high strength (1137–1360 MPa), better thermal stability (238 °C) and superior bonding characteristics revealed by standard investigations promotes TFF as a promising natural fiber reinforcement for many composite applications. Low cost and competent performance can be achieved with this natural fiber when reinforced in polymer matrix.

Physical, chemical, thermal and crystalline properties of new natural fiber extracted from the root of Ficus Religiosa tree(FRRF) are reported in this study. The chemical analysis and X-ray diffraction (XRD) analysis results ensured the presence of higher quantity of cellulose content (55.58 wt%) in the FRRF. Nuclear Magnetic Resonance (NMR) spectroscopy analysis is transported away to support the chemical groups present in the considered fibre. Thermal stability (325 °C), maximum degradation temperature (400 °C) and kinetic activation energy (68.02 kJ/mol.) of the FRRF areestablished by the thermo gravimetric analysis. The diameter (25.62 μm) and density (1246 kg/m3) of the FRRF have been found by the physical analysis. Scanning electron microscope analysis (SEM) and Atomic force microscope analysis (AFM) outcomes revealed that FRRF has the relatively smoothest surface. Altogether the above outcomes proved that novel FRRF is the desirable reinforcement to fabricate the fiber reinforced composite materials.

Biogas production from biomass is an eco-friendly approach that offers renewable energy generation, waste recycling, biofertilizer production along with maintaining environmental quality. Anaerobic decomposition is a familiar practice used for biogas production in worldwide, whereas only few substrates were convenient for attaining desired methane concentration in biogas. Hence, further advancements are necessary for the exploration and utilization of various complex organic materials for the purpose. This article gives a clear outlook on potential of various biomass for biogas production, necessity of pretreatment, applicability of microbial/enzyme addition, maintenance of various process parameters, formulation of suitable digester designs and future scope of this area. The livestock wastes and agricultural wastes possess high energy generation potential (71%) and sustainable utilization of such wastes are admirable to commercialize biogas production in future. Hence, selection of biomass through biochemical methane potential (BMP) analysis and biomass pretreatment prior to anaerobic decomposition is adequate to improve the quality and quantity of generated biogas. Addition of effective microorganisms or respective enzymes along with the employment of suitable bioreactors, are other perspectives to enhance decomposition. The single-stage and multi-stage systems possess much attention than other types of reactors since that offers accurate process management at four different stages of decomposition. Moreover, the maintenances of optimum pH, temperature, volatile fatty acids, carbon/nitrogen ratio, etc. are crucial to evade system unsteadiness during decomposition. Since comprehensive mathematical models are appropriate to make the anaerobic decomposition process economically feasible and advancement with these forecasts are adequate to commercialize this technology in the future.

Natural fibers from bio-renewable sources have the potential to be used as an alternate reinforcement for the perilous synthetic fibers. The hazards of prolong exposure to such fibers are quite serious, which demands scientific intervention. Natural fibers, like the one investigated – Cissus quadrangularis stem fiber (CQSF), have proven thermomechanical properties for polymer composite reinforcement. Enhancing fiber–matrix bonding through chemical treatments such as mercerization and deposition of cotton linters-based microcrystalline cellulose powder on fiber surface are comprehensively investigated. The mechanical properties of treated fiber composites reveal good bonding features through scanning electron microscopy analysis, which are further substantiated by the evaluation of mechanical property. In particular, 5 wt.% cellulose powder-treated CQSF/polyester composites showed distinguishable enrichment in mechanical and water absorption characteristics.

Fiber reinforced polymer composites are replacing many metallic structures due to its high specific strength and modulus. However commonly used man-made E-glass fibers are hazardous for health and carcinogenic by nature. Comprehensive characterization of Cissus quadrangularis root fiber such as anatomical study, chemical analysis, physical analysis, FTIR, XRD, SEM analysis and thermo gravimetric analysis are done. The results are very encouraging for its application in fiber industries, composite manufacturing, etc. Due to its light weight and the presence of high cellulose content (77.17%) with very little wax (0.14%) provide high specific strength and good bonding properties. The flaky honeycomb outer surface and low microfibril angle revealed through electron microscopy contributes for its high modulus. The thermo gravimetric analysis indicates better thermal stability of the fiber up to 230°C, which is well within the polymerization process temperature.

The polymeric matrix Composite Materials is widely used for automotive and aeronautical industry applications due to its superior properties. The tribological properties of the Carbon Epoxy Composites with 5% of silane treated SiC and 10% of silane treated SiC which were added separately and it has been investigated experimentally by the dry sliding wear test using the Pin-on-Disc type wear test rig. The main parameters Sliding Speed (S), Applied Load (L) and Sliding Distance (D) which were considered for the experimental investigation and evaluated the dry sliding wear characteristics of composites. Under increased levels of loads and sliding velocity conditions higher wear loss was noted. The coefficient of friction values from the result shown that the increased value with addition in load and also sliding velocity. It results was compared that the Carbon Epoxy Composites containing ST - SiC Fillers having lower Coefficient of Friction than plain Carbon Epoxy Composites. From the observations maximum wear resistance were found and discussed.

Carbon fabric-reinforced epoxy composites with and without silicon carbide filler were prepared by hand lay-up technique followed by compression moulding. These composites were tested on a pin-on-disc wear tester. The dry sliding wear test conditions include different applied load and sliding velocity. In this study, friction and dry sliding wear behaviour of silicon carbide (SiC)-filled carbon fabric-reinforced epoxy (C-E) composites were investigated. The weight fraction of SiC filler was varied (0, 5 and 10 wt%) so as to obtain composite samples of three different compositions. Sliding wear experiments were conducted using a pin-on-disc wear tester. The tests were conducted at a fixed sliding distance by varying the applied load and sliding velocity. The results show that for increased load and sliding velocity, higher wear loss was recorded. Excellent wear characteristics were obtained with C-E containing SiC as filler. Especially, 10 wt% of SiC in C-E gave a low wear rate. Moreover, the results revea...

Land application of sludge as fertilizers is a way of disposal and recycling of sludge. However, public concern has arisen due to the fact that organic contaminants in sludge may ultimately enter the food chain. Hence the need arises to analyse the organic contaminants such as PAHs and OCPs in sludge. In this study, Soxhlet was utilised as the extraction method and the extracts subjected to extensive cleanup via either silica columns or solid phase extraction cartridges prior to analysis using gas chromatography or high performance liquid chromatography. Sludge samples were collected from the drying beds of oxidation ponds in three locations in South Johore. OCPs such as heptachlor, dieldrin and pp-DDT were detected in low amounts (52-159 mg/kg) whereas PAHs such as naphthalene, phenanthrene, fluoranthene and benzo(a)pyrene were detected in the range of 0.2-5.5 mg/kg dry mass. Subcritical water extraction (SWE) recovery studies of PAHs were also performed from spiked sludge samples. Although a recovery range of 41-68% was obtained using the SWE method, the results indicated the usefulness of the technique as an alternative to Soxhlet extraction for the analysis of PAHs in sludge samples.

Land application of sludge as fertilizers is a way of disposal and recycling of sludge. However, public concern has arisen due to the fact that organic contaminants in sludge may ultimately enter the food chain. Hence the need arises to analyse the organic contaminants such as PAHs and OCPs in sludge. In this study, Soxhlet was utilised as the extraction method and the extracts subjected to extensive cleanup via either silica columns or solid phase extraction cartridges prior to analysis using gas chromatography or high performance liquid chromatography. Sludge samples were collected from the drying beds of oxidation ponds in three locations in South Johore. OCPs such as heptachlor, dieldrin and pp-DDT were detected in low amounts (52-159 mg/kg) whereas PAHs such as naphthalene, phenanthrene, fluoranthene and benzo(a)pyrene were detected in the range of 0.2-5.5 mg/kg dry mass. Subcritical water extraction (SWE) recovery studies of PAHs were also performed from spiked sludge samples. Although a recovery range of 41-68% was obtained using the SWE method, the results indicated the usefulness of the technique as an alternative to Soxhlet extraction for the analysis of PAHs in sludge samples.

Olanzapine is an atypical antipsychotic that is reported to be effective without producing the disabling extrapyramidal side effects associated with the older, typical antipsychotic drugs.To determine the clinical effects and safety of olanzapine as compared with placebo, typical and other atypical antipsychotic drugs for schizophrenia and schizophreniform psychoses.The reviewers undertook electronic searches of Biological Abstracts (1980-1999), The Cochrane Library (Issue 2, 1999), EMBASE (1980-1999), MEDLINE (1966-1999), PsycLIT (1974-1999) and The Cochrane Schizophrenia Group's Register (October 2000). References of all identified studies were searched for further trials, and the reviewers contacted relevant pharmaceutical companies and authors of trials.All randomised clinical trials comparing olanzapine to placebo or any antipsychotic treatment for those with schizophrenia or schizophreniform psychoses.Data were independently extracted. For homogeneous dichotomous data the random effects relative risk (RR), the 95% confidence intervals (CI) and, where appropriate, the number needed to treat (NNT) were calculated on an intention-to-treat basis. For continuous data the reviewers calculated weighted mean differences.Twenty one trials are included. Attrition from olanzapine versus placebo studies was so great (olanzapine - 61%, placebo - 73% by six weeks, RR 0.85 CI 0.7-0.98, NNT 8 CI 5-40) that interpretation of results is problematic. Olanzapine appeared superior to placebo at six weeks for the outcome of 'no important clinical response' (RR 0.88 CI 0.8-0.98, NNT 8 CI 5-27) and global mental state scores. Although dizziness and dry mouth were reported more frequently in the olanzapine-treated group, this did not reach statistical significance. Tthe olanzapine group gained more weight. When compared to typical antipsychotic drugs, data from several small trials are incomplete; but, for the short term outcome of 'no important clinical response', olanzapine seem as effective as typical antipsychotics (n=2778, RR 0.9 CI 0.76-1.06). Brief Psychiatric Rating Scale (BPRS) data tended to be equivocal but Positive and Negative Syndrome Scale (PANSS) rating of total score and negative and positive symptom sub-scores favoured olanzapine. With high attrition in both groups (olanzapine - 36%, typical drug - 49% by 6 weeks, n=2738, RR 0.85 CI 0.66-1.1; olanzapine - 83%, typical drug - 90% by 1 year, n=2738, RR 0.9 CI 0.86-1.02), the assumptions included in all continuous data are considerable. Participants allocated olanzapine experienced fewer extrapyramidal side effects than people given haloperidol. Weight change data for the short term are not conclusive (n=2455, WMD 0.8kg CI -0.6-2.2) but the three to 12 month results suggest an average gain of four kilograms (n=233, WMD 4 CI 0.3-7.8). It is difficult to distinguish between olanzapine and other atypical drugs, although it may cause fewer extrapyramidal side effects than risperidone (n=339, RR 0.6 CI 0.4-0.9, NNH 8 CI 4-29). Olanzapine did cause more weight gain than its comparators but current data are not statistically significant (3-12 months, n=535, WMD 2.2kg CI -0.6-5). One study (n=180) found no clear differences between olanzapine and clozapine for people with treatment-resistant illness.The large proportions of participants leaving the studies early, in the large multi-centre trials makes it difficult to draw firm conclusions on clinical effects. For people with schizophrenia olanzapine may offer antipsychotic efficacy with fewer extrapyramidal side effects than typical drugs but more weight gain. Large, long-term randomised trials with participants, interventions and primary outcomes that are familiar to those wishing to help those with schizophrenia are long overdue.