The Development of a Temporomandibular Force Simulator to Study Craniofacial Strain In-Vitro

An in-vitro musculoskeletal loading simulator was developed to replicate the internal forces of mastication, and then employed in a comparison of clinically relevant facial fracture repairs. Muscle forces are simulated by pneumatic pistons via 3D printed mounts that are reverse-engineered from CT scan to match muscle attachment sites, which are adhered to bone in order to simulate native stress distributions. Bite force and bone strain pattern of the craniofacial structure under load were measured using a force sensor and strain gauges respectively. In a series of five fresh-frozen cadaveric heads, it was found that strain patterns of the craniofacial structure were different between internal and external loading. In a zygomatic complex fracture with an intact zygomatic arch, an infraorbital rim plate made no difference in strain pattern. However, with a fractured arch, a repair done without an infraorbital rim plate better restored the strain pattern of an intact craniofacial structure

Environmental performance of external roller blinds retrofit for offices in the United Kingdom

Abstract Fixed external shading devices, such as louvers, are widely used to combat solar gains that can lead to excessive overheating. External roller blinds, although commonly used in mainland Europe, are rarities in the UK. External roller blinds are retractable shading devices formed of horizontal slats that roll up into a casing above a window opening. They are a well-developed technology with distinct advantages over fixed external shading devices. When fully extended the blinds block solar radiation externally reducing heat gain in summer, in the winter they add thermal resistance and reduce heat loss through windows. Appropriate design and applications of external roller blinds have the potential to improve the sustainability of buildings. This paper reports on an on-going applied research project that investigates the effect of external roller blinds on the internal thermal environment and potential advantages to the sustainability of retrofitting office buildings in the UK. The first part of the paper describes a proof of concept study in which an in-situ external roller blind was installed in a 'test' room and its summertime thermal performance was compared with that of a 'control' room under the same external climatic conditions. Dynamic thermal analysis was carried out to establish the annual thermal performance of the blind, including impact on cooling and heating energy requirements. Associated annual carbon dioxide emissions were established and the blind was discovered to reduce the greenhouse gas emissions (CO 2e ) by 15% annually, majority of which is reduction in requirement for heating. The life cycle impact of the blind was investigated. Individual process contributing to the production, manufacture, decommissioning and transport of the blind were assessed in terms of their greenhouse gas emissions. Under the conditions of the concept study scenario and taking into account the recycle of the components, the external roller blind in operation is estimated to take approximately six months to save enough to compensate the embodied greenhouse gas emissions mainly due to the manufacturing process. have demonstrated there is significant potential of using external roller blinds to reduce the operational and life cycle greenhouse gas emissions of buildings in the United Kingdom

Phakic anterior chamber intraocular lens (Verisyse™) implantation in children for treatment of severe ansiometropia myopia and amblyopia: Six-month pilot clincial trial and review of literature

Amir Pirouzian1,3, Kenneth C Ip2, Henry S O’Halloran31The Permanente Medical Group, Santa Clara, CA, USA; 2The Permanente Medical Group, San Francisco, CA, USA; 3Rady’s Children’s Hospital of San Diego, San Diego, CA, USAPurpose: The current study aims to evaluate both safety and efficacy of Verisyse™ (AMO, Irvine, CA) phakic anterior chamber intraocular lens (IOL) in the reduction of clinically significant (>-8 D) myopic anisometropia in children who are noncompliant to traditional medical treatment including spectacle correction or contact lenses.Design: Retrospective interventional case series.Methods: Six anisometropic myopic pediatric patients in one practice were identified through chart-review. None of the patients were compliant with specatacle correction or contact lens wear and as a result had dense amblyopia of less than 20/400 by Snellen or Allen visual acuity (mean <20/400). All patients underwent Verisyse™ phakic IOL implantation in the more myopic eye by one surgeon (AP). Pre- and post-operative visual acuity, anterior/posterior segment examination, stereoacuity, axial biometry measurements, cycloplegic refraction, and endothelial cell counts were performed in all patients whenever feasible.Results: The age of patients ranged from 5–11 years. The mean post-operative follow-up time was six months from the time of IOL insertion. Improvement in visual acuity >6 lines was achieved in four patients (mean visual acuity of 20/70 at six months). Improvement in stereoacuity was noted in all six patients (from total mean zero seconds-arc to six-months post-operative mean of 500 seconds-arc by randot stereoacuity testing). Improvement of >2 lines of visual acuity lines was achieved in the other two patients. No patient lost any lines of visual acuity. Enhanced physical activity, coordination, and improved social interaction were noted in patients and were reported by the parents. No intra/post-operative complications were noted.Discussion: Irreversible or intractable amblyopia secondary to severe anisometropic myopia is a serious medical concern in the pediatric population. Failure of compliance with contact lens therapy consistently leads to visual loss. Anterior chamber phakic IOLs may provide a safe alternative in treatment of noncompliant anisometropic myopic patients who do not accept spectacle wear or contact lens therapy.Conclusion: To reduce or eliminate highly significant anisometropic myopia in children who are noncompliant with traditional medical treatment, phakic anterior chamber IOL implantation may be considered as an alternative modality of treatment. Keywords: amblyopia, anisometropia, myopia, intraocular lens implan

The Impact of Double Skin Façade on the Energy Consumption of Office Buildings under the Tropical Brazilian Climate

Double skin façade (DSF) is an attractive architectural element in modern office buildings that, while giving a transparent appearance to buildings, can potentially be able to moderate the indoor thermal conditions and reduce energy demands. Developments in warmer climate countries such as Brazil are beginning to consider the application of DSF technology as a solution to improve thermal and energy performance in their buildings. Building upon the experience of a comprehensive research programme on the study of the thermal performance of office buildings with DSF, from which key design parameters affecting the thermal behaviour of DSF have been identified and evaluated, this study aims to examine the impact on energy consumptions. Using an office building model with an optimised DSF, this study assesses the energy consumptions when the building is fully air conditioned or operated under a mixed mode ventilation strategy. Models with similar characteristics but with single skin façade are also studied for comparison. Computational models developed for this study are evaluated using the dynamic simulation program IESVE which integrates building fabric thermal behaviour and environmental systems operating under the climatic conditions of the Brazilian city Rio de Janeiro. The results indicate that natural ventilation can provide the necessary thermal comfort in over 34% of the year in the building model with DSF under mixed mode ventilation strategy, that can potentially reduce 21% of annual cooling energy when compared to the fully air conditioned model. However, energy savings due to the addition of DSF alone are relatively small - 15% in full air conditioned model and 6% in mixed mode ventilation model. The benefit to thermal energy consumption is therefore marginal. However, comprehensive whole life evaluation is needed to provide a holistic assessment when other beneficial contributors, such as lighting, smart glazing and integrated PV are taken into consideration

Life cycle impacts of shower water waste heat recovery: Case study of an installation at a university sport facility in the UK

Recovering heat from waste water discharged from showers to preheat the incoming cold water has been promoted as a cost-effective, energy-efficient, and low-carbon design option which has been included in the UK’s Standard Assessment Procedure (SAP) for demonstrating compliance with the Building Regulation for dwellings. Incentivized by its carbon cost-effectiveness, waste water heat exchangers (WWHX) have been selected and incorporated in a newly constructed Sports Pavilion at the University of Brighton in the UK. This £2-m sports development serving several football fields was completed in August 2015 providing eight water- and energy-efficient shower rooms for students, staff, and external organizations. Six of the shower rooms are located on the ground floor and two on the first floor, each fitted with five or six thermostatically controlled shower units. Inline type of WWHX were installed, each consisted of a copper pipe section wound by an external coil of smaller copper pipe through which the cold water would be warmed before entering the shower mixers. Using the installation at Sport Pavilion as the case study, this research aims to evaluate the environmental and financial sustainability of a vertical waste heat recovery device, over a life cycle of 50years, with comparison to the normal use of a PVC-u pipe. A heat transfer mathematical model representing the system has been developed to inform the development of the methodology for measuring the in-situ thermal performance of individual and multiple use of showers in each changing room. Adopting a system thinking modeling technique, a quasi-dynamic simulation computer model was established enabling the prediction of annual energy consumptions under different shower usage profiles. Data based on the process map and inventory of a functional unit of WWHX were applied to a proprietary assessment software to establish the relevant outputs for the life-cycle environmental impact assessment. Life-cycle cost models were developed and industry price book data were applied. The results indicated that the seasonal thermal effectiveness was over 50% enabling significant energy savings through heat recovery that led to short carbon payback time of less than 2years to compensate for the additional greenhouse gas emissions associated with the WWHX. However, the life-cycle cost of the WWHX is much higher than using the PVC pipe, even with significant heat recovered under heavy usage, highlighting the need to adopt more economic configurations, such as combining waste water through fewer units, in order to maximize the return on investment and improve the financial viability