Research on Ventilation and Heat Insulation Layer Design of Split-Type Roof Greening Based on Topological Interlocking Principle

In this paper,the roof ventilation and heat insulation layer modules are combined with the roof greening,and each module is assembled through the principle of topological interlocking.The assembly of these modules does not require any rivets or cement mortar,and the structural stability of the overall assembled roof is achieved only through the interlocking and limiting the movements of the interlocked units.The green roof designed in this paper has strong applicability and can be applied to roofs of different shapes.Such a roof can not only meet the aesthetic needs,but also beautify the urban environment and reduce carbon emissions.

Preparation of ultra-fine grain Ni-Al-WC coating with interlocking bonding on austenitic stainless steel by laser clad and friction stir processing

The ultra-fine structured Ni?Al?WC layer with interlocking bonding was fabricated on austenitic stainless steel by combination of laser clad and friction stir processing (FSP). Laser was initially applied to Ni?Al elemental powder preplaced on the austenitic stainless steel substrate to produce a coating for further processing. The as-received coating was subjected to FSP treatment, processed by a rotary tool rod made of WC?Co alloy, to obtain sample for inspection. Microstructure, phase constitutions, hardness and wear property were investigated by methods of scanning electronic microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) microanalysis, and X-ray diffraction (XRD), hardness test alongside with dry sliding wear test. The results show that the severe deformation effect exerted on the specimen resulted in an ultra-fine grain layer of about 100μmin thickness and grain size of 1?2μm. Synergy between introduction of WC particles to the deformation layer and deformation strengthening contributes greatly to the increase in hardness and friction resistance. An interlocking bonding between the coating and matrix which significantly improves bonding strength was formed due to the severe deformation effect.

Comparative study of intertrochanteric fracture fixation using proximal femoral nail with and without distal interlocking screws

BACKGROUND Intertrochanteric(IT)fracture is one of the most common fractures seen in an orthopaedic practice.Proximal femoral nailing(PFN)is a common modality of fixing IT femur fracture.We retrospectively studied whether a PFN with two proximal lag screws can be done without distal interlocking screws in the 31-A1 and 31-A2 fracture patterns according to the Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association(AO/OTA)guidelines for IT femur fractures.AIM To compare the outcomes of IT fractures(AO/OTA 31-A1 and 31-A2)treated by PFN with and without distal interlocking screws.METHODS We carried out a retrospective study of 140 patients in a tertiary care centre who had AO/OTA type 31-A1 and 31-A2 IT fractures.We divided the patients into two groups,in which one of the groups received distal interlocking screws(group 1)and the other group did not(group 2).The subjects were followed up for a mean period of 14 mo and assessed for radiological union time,fracture site collapse,mechanical stability of implant,and complications associated with the PFN with distal interlocking and without distal interlocking.Then,the results were compared.RESULTS PFN without distal interlocking screws has several advantages and gives better results over PFN with distal interlocking screws in the AO/OTA 31-A2 fracture pattern.However,similar results were observed in both groups with the fracture pattern AO/OTA 31-A1.In patients with fracture pattern AO/OTA 31-A2 treated by PFN without distal interlocking screws,there were minimal proximal lockrelated complications and no risk of distal interlock-related complications.The operative time,IITV radiation time and time to radiological union were reduced.These patients also had better rotational alignment of the proximal femur,and the anatomy of the proximal femur was well maintained.It was also noted that in the cases where distal interlocking was performed,there was a gradual decrease in neck shaft angle,which led to varus collapse and failure of bone-implant construct in 21.40%.CONCLUSION In fracture pattern AO/OTA 31-A2,PFN without distal interlocking had better results and less complications than PFN with distal interlocking.

Interlock可解脱弹簧圈系统在冠状动脉-肺动脉瘘栓塞术中的应用

目的探讨Interlock可解脱弹簧圈系统应用于冠状动脉-肺动脉瘘栓塞术的安全性及有效性。方法回顾性分析2016年12月23日至2017年9月7日于中国医学科学院阜外医院选用Interlock可解脱弹簧圈系统行冠状动脉-肺动脉瘘栓塞术的6例冠状动脉-肺动脉瘘患者临床资料,其中包括男性2例,女性4例。所有患者均常规采用右侧桡动脉入径行冠状动脉造影以明确诊断,沿导管置入并释放Interlock可解脱弹簧圈于瘘管或瘤腔内,栓塞后行选择性冠状动脉造影评价疗效,观察术中及术后有无并发症发生。结果 6例选用Interlock可解脱弹簧圈行冠状动脉-肺动脉瘘栓塞术的患者均手术成功,无血管损伤及心肌梗死等术中并发症发生。有4例合并动脉瘤形成,其中3例应用弹簧圈填塞在动脉瘤体,1例栓塞在动脉瘤近心端瘘管。术中共用Interlock可解脱弹簧圈18枚,其中3枚为钻石型,15枚为普通2D型;弹簧圈直径为2～12 mm,长度为2.3～30 cm;瘘口直径为2～3 mm。即刻行选择性冠状动脉造影,其中3例为完全栓塞,3例有少量残余分流。术后所有患者胸闷、胸痛症状均得以缓解;超声心动图提示无异常血流,X线胸片提示弹簧圈位置、形态良好,心电图检查无新发心律失常或心肌缺血等改变。随访12个月,无心肌梗死、心源性休克、心室颤动、心室扑动、心脏破裂或猝死等主要不良心血管事件发生。结论 Interlock可解脱弹簧圈系统可控性高、安全性好,尤其适用于伴有动脉瘤形成、血管迂曲需要准确定位的冠状动脉-肺动脉瘘患者介入治疗。

Modeling the relationship of land use change and some geophysical indicators for the interlock area of farming and pasturing in China

This paper discusses land-use changes in the interlock area of farming and pasturing (IAFP) in northern China. It presents detailed analyses of land-use features in the IAFP, which are controlled by the macro geomorphic units and geophysical conditions-constraints or advantages. Additionally, it selects some indicators, according to the availability in acquiring and processing their quantitative data, to analyze the canonical correlations between the typical conversion of grassland and geophysical conditions. The preliminary study indicates that the physical conditions are of great advantages to the development of grassland. There exists significant correlation between land use change and some geophysical conditions.

ELASTIC BEHAVIOR ANALYSIS OF 3D ANGLE-INTERLOCK WOVEN CERAMIC COMPOSITES

A micromechanical model for elastic behavior analysis of angle-interlock woven ceramic composites is proposed in this paper. This model takes into account the actual fabric structure by considering the fiber undulation and continuity in space, the cavities between adjacent yarns and the actual cross-section geometry of the yarn. Based on the laminate theory, the elastic properties of 3D angle-interlock woven ceramic composites are predicted. Different numbers of interlaced wefts have almost the same elastic moduli. The thickness of ceramic matrix has little effect on elastic moduli. When the undulation ratio increases longitudinal modulus decreases and the other Young＇s moduli increase. Good agreement between theoretical predictions and experimental results demonstrates the feasibility of the proposed model in analyzing the elastic properties of 3D angle-interlock woven ceramic composites. The results of this paper verify the fact that the method of analyzing polyester matrix composites is suitable for woven ceramic composites.

Interlocked MXene/rGO aerogel with excellent mechanical stability for a health-monitoring device

Two-dimensional(2D)materials have attracted considerable interest thanks to their unique electronic/physical-chemical characteristics and their potential for use in a large variety of sensing applications.However,few-layered nanosheets tend to agglomerate owing to van der Waals forces,which obstruct internal nanoscale transport channels,resulting in low electrochemical activity and restricting their use for sensing purposes.Here,a hybrid MXene/rGO aerogel with a three-dimensional(3D)interlocked network was fabricated via a freeze-drying method.The porous MXene/rGO aerogel has a lightweight and hierarchical porous architecture,which can be compressed and expanded several times without breaking.Additionally,a flexible pressure sensor that uses the aerogel as the sensitive layer has a wide response range of approximately 0-40 kPa and a considerable response within this range,averaging approximately 61.49 kPa^(-1).The excellent sensing performance endows it with a broad range of applications,including human-computer interfaces and human health monitoring.

Olecranon anatomy:Use of a novel proximal interlocking screw for intramedullary nailing,a cadaver study

AIM: To define the optimum safe angle of use for an eccentrically aligned proximal interlocking screw(PIS) for intramedullary nailing(IMN).METHODS: Thirty-six dry cadaver ulnas were split into two equal pieces sagitally. The following points were identified for each ulna: the deepest point of the incisura olecrani(A), the point where perpendicular lines from A and the ideal IMN entry point(D) are intersected(C) and a point at 3.5 mm(2 mm safety distance from articular surface + 1.5 mm radius of PIS) posterior from point A(B). We calculated the angle of screws inserted from point D through to point B in relation to D-C and B-C. In addition, an eccentrically aligned screw was inserted at a standard 20° through the anterior cortex of the ulna in each bone and the articular surface wasobserved macroscopically for any damage.RESULTS: The mean A-C distance was 9.6 mm(mean ± SD, 9.600 ± 0.763 mm), A-B distance was 3.5 mm, C-D distance was 12.500 mm(12.500 ± 1.371 mm) and the mean angle was 25.9°(25.9°± 2.0°). Lack of articular damage was confirmed macroscopically in all bones after the 20.0° eccentrically aligned screws were inserted. Intramedullary nail fixation systems have well known biological and biomechanical advantages for osteosynthesis. However, as well as these well-known advantages, IMN fixation of the ulna has some limitations. Some important limitations are related to the proximal interlocking of the ulna nail. The location of the PIS itself limits the indications for which intramedullary systems can be selected as an implant for the ulna. The new PIS design, where the PIS is aligned 20°eccentrically to the nail body, allows fixing of fractures even at the level of the olecranon without disturbing the joint. It also allows the eccentrically aligned screw to be inserted in any direction except through the proximal radio-ulnar joint. Taking into consideration our results, we now use a 20° eccentrically aligned PIS for all ulnas. In our results, the angle required to insert the PIS was less than 20° for only one bone. However, 0.7° difference corresponds to placement of the screw only 0.2 mm closer to the articular surface. As we assume 2.0 mm to be a safe distance, a placement of the screw 0.2 mm closer to the articular surface may not produce any clinical symptoms.CONCLUSION: The new PIS may give us the opportunity to interlock IMN without articular damage and confirmation by fluoroscopy if the nail is manufactured with a PIS aligned at a 20.0° fixed angle in relation to the IMN.

Open Fracture Tibia Treated by Unreamed Interlocking Nail. Long Experience in El-Bakry General Hospital

Background: Internal splintage of open tibial fractures had gained acceptance as a preferred method of early stabilization of such injuries. Patients and Methods: Fifty-five patients had been operated upon. They were followed from July 2008 to March 2013 (56 months) with an average time of 39 months. The final results had been evaluated through a scheme including 7 parameters: pain, union, malunion, infection, range motions of nearby joints, implant and technical failure and activity and returning to the same work. Results: According to previous parameters, union was achieved in 52 cases (94.5%) at an average time of 20 weeks (16 - 52 weeks) with 5.5% incidence of nonunion. Excellent and good ranges of knee and ankle motions were achieved at final follow-up visit in 49 cases (89.09%). The incidence of complication was acceptable mainly malunion 7.3%, deep infection 12.7%, implant and technical failure 9.1% full activity and returning to the same work achieved in 89.1%. The overall net results of our series are as follows: excellent—19 cases (34.5%), good—27 cases (49.1%), fair—6 cases (10.9%) and poor—3 cases (5.5%). Conclusion: Utilizing unreamed interlocking nail for open tibial fractures is a good method of treatment particularly those of grade (II), and (IIIA).

Verifying the accuracy of interlocking tables for railway signalling systems using abstract state machines

Railway transportation system is a critical sector where design methods and techniques are defined by international standards in order to reduce possible risks to an acceptable minimum level. CENELEC 50128 strongly recommends the utilization of finite state machines during system modelling stage and formal proof methods during the verifi- cation and testing stages of control algorithms. Due to the high importance of interlocking table at the design state of a sig- nalization system, the modelling and verification of inter- locking tables are examined in this work. For this purpose, abstract state machines are used as a modelling tool. The developed models have been performed in a generalized structure such that the model control can be done automatically for the interlocking systems. In this study, NuSMV is used at the verification state. Also, the consistency of the developed models has been supervised through fault injection. The developed models and software components are applied on a real railway station operated by Metro Istanbul Co.

Design of Railway Computer Interlocking Search Algorithm and Implementation of Interlocking Software

The computer interlocking system has a wide application in realizing interlocking control between the switch, the signal, and the track circuit in station. Due to the similarity between the binary tree and the station-type data structure, the actual station route search method and the recursive algorithm are combined inorder to realize the computer interlocking route search. On this basis, through the design of switch class, track circuit class and signal machine class, by using C++ object-oriented the management of station data structure and entity object are realized, and then the crowding alarm, switch operations and so on in computer interlocking software. Taking the implementation of 5# station computer interlocking software as an example and based on are realized C++ the object-oriented computer interlocking software is written to provide a reference for realizing the railway computer interlocking training system function.

Experimental studies on interface mechanism of interlocking attachment of porous titanium

The feature of porous titanium is that new bone trabecular tissue could ingrow intoits pores and produce interlocking attachment.The spherical TC4 powder and titanium fiberwere seperately implanted into the femurs of 24 dogs.The pore size of the samples was0.24mm and their rates of porosity were 40%～50%.After 3 months,the interface shearstrength examined by straight pulling test,was over 4.60±0.36MPa.Scanning electronmicroscopy showed that there were new bone components in the porous layer.Lightmicroscopy also revealed that there were new bone lacunae and their pathways in it.Thedepth of the reforming bone was 3 mm.Interface shear strength of the new bone in the po-rous layer might meet the need of load bearing.Porous materials would prevent the artificialjoint from loosening and thus help to develop a new service clinically.

Dimensional Properties and Stretchability of Cotton Interlock with Missing Needle Fabrics

The dimensional properties and uniarial stretchability of cotton interlock and interlock with missing needle are discussed on the basis of definition system for double knits. K values used widely to describe the dimensional properties of plain knitted structures are developed into the study of double knitted structures in this paper. K values are not constants, the numerical values of which will depend on the actual configuration of various knitted structures. It is suggested that the effect of knitted structures on dimensional properties and stretchability can be described by K values.

Comparison of straight median sternotomy and interlocking sternotomy with respect to biomechanical stability

AIM: To increase the stability of sternotomy and so decrease the complications because of instability. METHODS: Tests were performed on 20 fresh sheep sterna which were isolated from the sterno-costa joints of the ribs. Median straight and interlocking sternotomies were performed on 10 sterna each, set as groups 1 and 2, respectively. Both sternotomies were performed with an oscillating saw and closed at three points with a No. 5 straight stainless-stee wiring. Fatigue testing was performed in craniocaudal, anterio-posterior(AP) and lateral directions by a computerized materials-testing machine cycling between loads of 0 to 400 N per 5 s(0.2 Hz). The amount of displacement in AP, lateral and craniocaudal directions were measured and also the op-posing bone surface at the osteotomy areas were calculated at the two halves of sternum. RESULTS: The mean displacement in cranio-caudal direction was 9.66 ± 3.34 mm for median sternotomy and was 1.26 ± 0.97 mm for interlocking sternotomy, P < 0.001. The mean displacement in AP direction was 9.12 ± 2.74 mm for median sternotomy and was 1.20 ± 0.55 mm for interlocking sternotomy, P < 0.001. The mean displacement in lateral direction was 8.95 ± 3.86 mm for median sternotomy and was 7.24 ± 2.43 mm for interlocking sternotomy, P > 0.001. The mean surface area was 10.40 ± 0.49 cm2 for median sternotomy and was 16.8 ± 0.78 cm2 for interlocking sternotomy, P < 0.001. The displacement in AP and cranio-caudal directions is less in group 2 and it is statistically significant. Displacement in lateral direction in group 2 is less but it is statistically not significant. Surface area in group 2 is significantly wider than group 1.CONCLUSION: Our test results demonstrated improved primary stability and wider opposing bone surfaces in interlocking sternotomy compared to median sternotomy. This method may provide better healing and less complication rates in clinical setting, further studies are necessary for its clinical implications.

Design of a personnel safety interlock system for proton therapy

Proton therapy is the most advanced radiotherapy approach in the world,and causes less damage to normal human tissue than traditional radiotherapy.Because the treatment process produces a high-energy proton beam,the personnel safety interlock system mainly considers measures to protect personnel from radiation hazards during beam preparation and the beam release process.Unlike other safety interlock systems,the personnel safety interlock system designed in this study focuses on the safety and stability of the system itself.The hardware and software of important interlock control loops are designed and developed according to the requirements of Safety Integrity Level 3 specified by IEC61508.A set of redundant ring networks was developed to ensure that damage to a certain network line does not affect the normal operation of the system.A set of friendly operation interfaces and data storage systems were developed to ensure that the operator can monitor the data in real time and trace the data.The personnel safety interlock system mainly includes a beam enabling function,clearance function,and emergency stop function.The system was put into actual use and successfully ensured personnel safety.

Near is more:learning efficiency in research and development innovation among interlocking firms

Research question/issue:This study examines whether geographic proximity produces a proximity preference as interlocking firms observe each other and learn innovative behaviors through information transmission among interlocking directors.Research findings/insights:We study the performance of A-share-listed companies in China from 2007 to 2017 on the basis of resource dependence theory,agglomeration effect theory,and Porter’s competitive theory.When target firms learn about research and development–related innovation behaviors from interlocking firms closer to them,they experience more efficient learning effects and have improved convergent traits.Moreover,this proximity advantage increases the willingness of the target firm to communicate with and learn from interlocking firms closer to them.Highly developed areas and research and development–intensive industries positively affect the learning efficiency of interlocking firms.Theoretical/academic implications:Our conclusion is consistent with resource dependence theory;target firms in highly developed areas are more willing to imitate and study nearby interlocking firms to maintain their peer relations,innovation potential,and competitiveness.Our conclusion is also consistent with competition theory,which states that the exchange of information between target firms in highly research and development–intensive industries and distant interlocking firms increases innovation differentiation,innovation potential,and competitiveness,even when such exchange has a high cost.Practitioner/policy implications:The results support resource dependence theory and peers’effects.The information obtained by interlocking directorates through external social relations guides firm decision-making,and closer distances reveal more obvious effects.

Application of double-layer Ether CAT and optical fiber interlock net in short circuit protection

The selectivity of short circuit protection of high voltage lines in coal mines cannot be realized by existing protection systems. To solve this problem, a scheme based on double layer Ether CAT and optical fiber interlock net was proposed. The system is mainly composed of double layer Ether CAT, optical fiber interlock net, ground monitoring station, underground control stations and integrated protection devices with Ether CAT communication interface and interlock interface. Double layer Ether CAT and optical fiber interlock net cooperate with each other, when one is interrupted, the other net carl realize selectivity of short circuit protection independently, Results of test show that the system can achieve selectivity of short circuit protection reliably, determine the fault location quickly, shorten troubleshooting time and improve safety and reliability of the power network in coal mines.

Investigation of the Effect of the Addition of Petroleum Waste to Interlocking Bricks Constituent

Incinerator ash was investigated for its potential use as a replacement for sand and cement in concrete interlocking bricks. The physical characteristics of the raw materials were examined. Two sets of mixes were prepared. For the first set, sand and water quantities were fixed while incinerator ash was used at 0% to 100% replacement by weight for cement in steps of 10%. In the second set, incinerator ash was used at 0% to 100% replacement by weight for sand while cement and water quantities was fixed. The mixing proportions for cement, sand and water were 1:3:0.7, respectively. Compressive strength and leachability tests were performed on the specimens. Results showed that the replacement of sand by incinerator ash up to 40% exhibited higher compressive strength than the control mix (0% incinerator ash) after 28 days curing. Maximum compressive strength of 33.33N/mm2 was obtained after 28 days curing using using 20% incinerator ash substitution for sand. Replacement of cement by incinerator ash up to 20% exhibited higher compressive strength than the control mix. Compressive strength of 28.2 N/mm2 was achieved after 28 days curing period using a 20% ash substitution for cement. Leaching of heavy metals (Pb and Cd ) present in the ash was observed in concentrated nitric acid.

Influence of degree of interlock on confined strength of jointed hard rock masses

The strength of jointed rock mass is strongly controlled by the degree of interlock between its constituent rock blocks.The degree of interlock constrains the kinematic freedom of individual rock blocks to rotate and slide along the block forming joints.The HoekeBrown(HB)failure criterion and the geological strength index(GSI)were developed based on experiences from mine slopes and tunneling projects in moderately to poorly interlocked jointed rock masses.It has since then been demonstrated that the approach to estimate the HB strength parameters based on the GSI strength scaling equations(called the‘GSI strength equations’)tends to underestimate the confined peak strength of highly interlocked jointed rock masses(i.e.GSI>65),where the rock mass is often non-persistently jointed,and the intact rock blocks are strong and brittle.The estimation of the confined strength of such rock masses is relevant when designing mine pillars and abutments at great depths,where the confining pressure is high enough to prevent block rotation and free sliding on block boundaries.In this article,a grain-based distinct element modeling approach is used to simulate jointed rock masses of various degrees of interlock and to investigate the influences of block shape,joint persistence and joint surface condition on the confined peak strengths.The focus is on non-persistently jointed and blocky(persistently jointed)rock masses,consisting of hard and homogeneous rock blocks devoid of any strength degrading defects such as veins.The results from this investigation confirm that the GSI strength equations underestimate the confined strength of highly interlocked and non-persistently jointed rock masses.Moreover,the GSI strength equations are found to be valid to estimate the confined strength of persistently jointed rock masses with smooth and non-dilatant joint surfaces.

Results of Dynamic Interlock Nailing in Distal Tibial Fractures

A study was performed in adults to determine the efficacy of closed reduction and intramedullary nailing in dynamic mode on union, implant failure and incidence of malalignment in patients who sustained an extra-articular fracture of the distal tibia. Methods: Between January 2007 and December 2013, one hundred and twelve patients of distal tibia that involved the distal 6 cm of the tibia were treated at our hospital with reamed intramedullary nailing with use of two distal interlocking screws and one proximal screw in dynamic mode. The augmentation was done with poller screws whenever it was necessary. The nailing of fibular fractures was done in 27 cases. There were 85 males and 27 females with a mean age of 30.9 (range: 20 to 72). Eighty fractures were closed whereas 32 were grade 1 open fractures. Results: The average time to union of the closed fracture was 15.4 weeks (range: 12 – 28 weeks). The healing times for the primarily nailed compound Grade I averaged 17.8 (range: 15 - 34 weeks). After minimum follow-up of one year, rate of primary union was in 97.32%. One case of broken nail required revision surgery. There were three cases of delayed union and two cases of non union. In one case there was deep infection which required exchange nailing with antibiotic impregnated nail. There was breakage of interlocking screws in three cases but fracture had united. In twenty two cases acceptable malalignment of the tibia was observed after union. The outcome was determined at a minimum of one year in our study based on the criteria of Johner and Wruhs. Out of 112 patients, 79 patients had excellent results, 29 had good results and 4 had fair results. Conclusions: The dynamic osteosynthesis of distal tibia by interlocking nail and judicious use of poller screws is an effective alternative for the treatment of distal metaphyseal tibial fractures.