Horizontal Lifting Research Articles

Performance of Combined Woven Roving and Mat Glass-Fiber Reinforced Polymer Composites Under Absorption Tower Lifting Loads.

This study investigates the structural integrity of a glass-fiber reinforced polymer absorption tower during lifting operations, evaluating factors of safety and stress distribution for both horizontal and vertical scenarios. A key focus is the comparative analysis of surface and volumetric meshing techniques in finite element modeling. Results demonstrate that surface models achieve comparable stress predictions to computationally intensive volumetric models, significantly reducing computational demands without compromising accuracy. For instance, stress at the flange edge with holes was accurately captured using a surface model with 5675 elements (12.79 MPa), yielding similar results to a volumetric model requiring over 94,000 elements (13.37 MPa). Similar computational efficiency and agreement between modeling approaches were observed at the packing support ring-shell joint. Finite element analysis employing Hashin's failure criterion, informed by industry-standard experimental data, revealed safety factors ranging from 1.9 to 2.5 for horizontal lifting and four for vertical lifting. These safety factors indicate sufficient margins for safe operation. While these findings support the feasibility of both lifting methods, further investigation is recommended to address the lower safety factors observed in specific horizontal lifting scenarios. A comprehensive assessment incorporating industry standards, dynamic load effects, and potential mitigation strategies is crucial to ensure the long-term structural integrity of the GFRP absorption tower.

Revival of cultural textile arts: creation of innovative weaving technology for fabricating traditional Chinese non-fixed four-warp leno

China is hailed as a country with a long history of producing silk and is known for the development and evolution of various weaving structures. The non-fixed four-warp leno is an ancient textile that is well-known for its soft, thin, airy texture and high quality. Unfortunately, the production method and apparatus have been lost. This research thus focuses on the development of a novel weaving technology and system to produce the non-fixed four-warp leno. Its major mechanism involves (1) an innovative synchronized vertical and horizontal lifting system to alter the current rigid one that can only produce a simple fixed leno; (2) an effective distance control technology to achieve flexible yet accurate placement of warps for leno formation without limitations on leno pattern and structures; and (3) an alternative method for securing the clearance of the shed to eliminate undesirable twine. It will thus contribute to a breakthrough in weaving technology, functional textiles and aesthetic design. The development of mechanized weaving can enable mass production and mass coverage, eventually contributing to the transmission of special techniques and the sustainable development of high value-added textile products.

Research of telescopic variable Boom length system for flat Boom tower crane

The telescopic principle of its boom section is investigated using the luffing system of the horizontal lifting boom with telescopic operation as the aim. In order to ensure that the normal lifting and luffing work of the trolley can be ensured when the horizontal boom is telescoped and retracted, the support method of the rope system on the horizontal boom, including the lifting rope system, the luffing rope system, and the telescopic rope system, is studied. The procedure for locating the supporting pulley of the three rope systems is investigated, and the alteration in the length of the three ropes caused by the extension or contraction of the horizontal boom is examined. The boom system's force analysis is conducted, and the force expressions of each force member with the expansion and contraction of the boom are obtained, and the force state diagram of each force member is drawn by MATLAB software.

Studying the distribution of a tower crane support loads using computer modeling

Problem. The construction of modern industrial and civil structures is impossible to imagine without tower cranes. They are used in the construction of both low-rise and high-rise buildings and industrial structures. Tower cranes are simply irreplaceable in the construction of buildings, and in the construction of low-rise structures, these cranes have certain advantages over self-propelled jib cranes. Tower cranes are designed to mechanize construction and installation work, providing up to 98% of all lifting and handling operations during the installation of construction elements of buildings and structures, and are also widely used in various types of lifting operations. The advantages of tower cranes also include the optimal combination of virtually any vertical and horizontal lifting height to any point of the facility under construction. It is worth emphasizing the extremely large potential of the Ukrainian construction market and its need for a wide variety of tower crane models. Thus, tower cranes are one of the most popular types of equipment. Goal. The goal is to develop a methodology for determining the loads during operation on the supporting elements of a tower crane with a support circuit, taking into account the spatial nature of the load and identifying patterns of change in the distribution of loads on the supports during crane operation. In this work, the tasks are achieved by applying an advanced calculation methodology with the use of computer modeling tools that allow the use of labor-intensive calculation methods that take into account many factors.
 Methodology. The main objective of the work is to develop a methodology for determining the loads during operation on the supporting elements of a tower crane with a solid support contour, taking into account the spatial nature of the load and identifying patterns of change in the distribution of loads on the supports during crane operation. 
 Results. It was found that the load of the crane support elements is oscillatory with an amplitude of about 200 kN. When the crane boom is rotated by 135 degrees, support 4 can withstand the greatest load, which is 250 kN, and support 2 is almost unloaded – 5 kN. At a turn of β = 225 degrees, a similar situation occurs with supports 1 and 3, respectively. When the overhang changes, supports 1 and 4 can withstand the same loads in the range of 68 to 190 kN, and supports 2 and 3 can withstand loads from 190 to 50 kN. At the maximum outreach, the critical positions of the crane are when the boom angles are β=45 degrees and β=315 degrees, in which case the crane rests on almost three supports. Originality. This task is achieved by applying an advanced calculation methodology with the use of computer modeling tools that allow the use of labor-intensive calculation methods which take into account many factors. Practical value. Using the developed algorithm for calculating the loads on the crane supports, a computational experiment was conducted to determine the magnitude and nature of changes in the loads on the crane supports under different operating conditions: with different loads and variable outreaches, wind loads.

Mechanical characteristics analysis of horizontal lifting of subsea pipeline with different burial depths

Different burial depths have different effects on the mechanical characteristics of the horizontal lifting of subsea pipelines. With the consideration of the soil resistance to subsea pipelines, combined with the specific sea condition parameters of a certain sea area, and based on the lumped mass method, the subsea pipeline is discretized into a lumped mass model, the dynamic analysis model of the three-point horizontal lifting of subsea pipelines with different burial depths is established. The stress and bending of the pipelines with different burial depths are analyzed. The calculation results with different burial depths are compared. The variation of mechanical characteristics of the process of lifting horizontal pipelines with different buried depths is obtained. The results show that the change of burial depth has a significant influence on the effective tension of the pipeline. With the increase of the burial depth, the maximum degree of stretching of the pipeline first decreases and then increases. Within a certain depth range, burying the pipeline in the seabed can reduce both the effective tension and the intensity of the fluctuation of the effective tension when the pipeline is lifted. The change of burial depths for the shear action is mainly reflected in the numerical values of the shear force. There is no significant impact on the degree and variation fluctuation of the shear force. The conclusions can provide a certain theoretical reference for the design of the process of horizontal pipeline lifting.

Annealing-induced rearrangement behavior and heat-resistant regularity of layered assemblies of organo-modified inorganic nanoparticles with different initial orders

The rearrangement effect and maintenance characteristics of heat-resistant order on nanoparticle layered assemblies with different initial orders obtained by two types of film preparation methods were evaluated. The layered structure was prepared by transferring single particle layers on the water surface of an organo-modified magnetite, in which the surface of Fe3O4 nanoparticles having a diameter of 5 nm was modified with a long-chain fatty acid, onto a substrate as multiparticle layers. Two types of multiparticle layers were obtained by the Langmuir–Blodgett (LB) and horizontal lifting/Langmuir–Schafer methods. The initial order of the multiparticle layers was higher in the layered assemblies derived from the LB method. On the other hand, the nanoparticle layered assemblies derived from the horizontal lifting method were remarkably highly ordered by annealing at a mild temperature for a long time. The rearrangement effect at the mild temperature over a long period was considered to originate from the enhancement in the van der Waals interaction between the organo-modified chains on the surface of the inorganic nanoparticles. In other words, it is considered that thermal motion occurs to the layered structure in which a large number of single particle layers are laminated as the pseudo-crystal lattice induces the interaction between the organic molecular chains.

Efficient horizontal lifting and annealing method for creating alternating multilayer structures with hard and soft multi-particle layers

• Alternating multilayer structure was created by the horizontal lifting method. • The regularity of alternating multilayers was improved by annealing. • Rapid compression of the horizontal lifting method resulted in dechaining. • The desorbed chain was able to remove by the solvent. • Slow compression suppressed the occurrence of chain-desorption. An efficient process for manufacturing Nano-mille-feuille/alternating multi-particle layers was developed, in order to elucidate the origin of the physical properties associated with long-period stacking ordered structures. The conventional process employing the upstroke Langmuir-Blodgett method requires approximately five days. Comparatively, the developed process employing the horizontal lifting method, which involved two Langmuir troughs, was shortened to one day. Alternating multi-particle layer was obtained by dividing the horizontal, long trough into two sections, and alternate single-particle layers of polymer and inorganic nanoparticles were transferred to the substrate. However, out-of-plane X-ray diffraction confirmed that there was a significant decrease in the order of the layers. To compensate for any poor order, the samples were annealed at mild temperatures to rearrange the particles. Annealing at 50 °C for 60 h significantly improved the order of the layers (hereinafter layered order) in the alternating multi-particle layers. In addition, increasing the compression rate after horizontal adhesion induced desorption of the organically modified chain of alternating multi-particle layers, which also improved the layered order after annealing. Solvent treatment or low-speed compression can be used to prevent desorption of the components.

Investigation Of 3D Effects And Free-Surface Proximity Influence On The Flow Around A Hydrofoil Using PIV Measurements

An Eppler 817 (E817) hydrofoil was studied experimentally using two dimensions two components Particles Image Velocimetry (PIV) measurements. Both statistical and time-resolved series were used to study the effect of Reynolds number and angle of attack on the flow topologies and dynamics. Vortex shedding modes were observed over a range of low chord-based Reynolds numbers 400 ≤ Rec ≤ 20000 and four angles of attack ( α = 2◦, 6◦, 12◦ and 30◦). Those Reynolds numbers are scarce documented on such hydrofoil as they are far from usual operating conditions. However, those low Reynolds numbers allowed us to observe Reynolds number based transitions of the vortex shedding modes at a given angle of attack. The data were acquired on both an extruded 2D hydrofoil and a 3D "T-shaped" hydrofoil, composed of a vertical shaft (e.g. rudder on a boat) holding the horizontal lifting surface. The latter was used to investigate the influence of both the 3D shape and surface proximity on the hydrofoil’s behaviour through three different depths, ranging from 3.5 to 0.875 chords. Additional measurements from a 6-axis loads sensor were used to characterize the loss of performance due to the free-surface proximity.

Efficient quantum dot light-emitting diodes with ultra-homogeneous and highly ordered quantum dot monolayer

Regarding conventional quantum dot light-emitting diodes (QLEDs) fabricated by using the spin-coating (SC) technique, voids and interstitial spaces are inevitable due to unordered quantum dots (QDs) stacking, generating device leakage current under an external bias. In the present study, we fabricated an ultra-homogeneous and highly ordered QD monolayer by adopting the Langmuir-Blodgett (LB) technique. The QD monolayer was transferred as a emissive layer with a horizontal lifting (HL) method to a red QLED, which exhibited high performance with an external quantum efficiency (EQE) of 19.0% and lifetime (T95@100 cd m−2) of 13,324 h. When compared with the SC-based device, the EQE and lifetime were improved by 15% and 183% due to the compact and ordered QD monolayer that lowered the leakage current. Moreover, white QLEDs with stacked QD monolayers could be obtained at a low voltage of 4 V because LB technique is an organic-solvent-free approach avoiding interlayer mixing and controlling the QD layer thickness precisely. In addition, we successfully fabricated an ultra-homogeneous large-area QD monolayer on a rectangular substrate with a size of 9 cm × 5 cm, indicating the promising size scalability of the LB-HL strategy.

Comparison of Single- Versus Dual-Vector Technique Using Facial Suspension Threads: A Cadaveric Study Using Skin Vector Displacement Analysis.

Facial suspension threads have been successfully used for facial soft-tissue repositioning. When using facial suspension threads, it is unclear which technique and/or material has the greatest lifting effect for the middle and lower face or which technique/material best reduces the appearance of the jowls. Three female and 2 male cephalic specimens of Caucasian ethnicity (65.2 ± 8.3 years; 20.72 ± 2.6 kg/m) were analyzed in an upright secured position. Polydioxanone and polycaprolactone bidirectional barbed facial suspension threads were introduced by an 18 G, 100 mm cannula. The single-vector technique aimed toward the labiomandibular sulcus, and the dual-vector technique aimed toward the labiomandibular sulcus and the mandibular angle. Computation of vertical lifting, horizontal lifting, and volume reduction at the jowls and along the jawline were calculated using 3D imaging. The dual-vector technique effected a greater vertical lifting effect (4.45 ± 2.78 mm vs 2.99 ± 2.23 mm) but a reduced horizontal lifting effect (0.33 ± 1.34 mm vs 0.49 ± 1.32 mm). The dual-vector technique effected less volume reduction at the jowls 0.32 ± 0.24 cc versus 0.41 ± 0.46 cc and less volume reduction along the jawline 0.46 ± 0.48 cc versus 0.87 ± 0.53 cc (dual-vector vs single-vector). This study provides evidence resulting from cadaveric observations for the overall nonsuperiority of the dual-vector technique compared with the single-vector technique.

The Influence of the Insertion Angle on Middle and Lower Face Tissue-Mechanics When Treating the Nasolabial Folds with Facial Suspension Threads-An Experimental Split-Face Cadaveric Study.

A novel treatment approach to address the nasolabial fold is the insertion facial suspension threads. However, there is a paucity of data available to guide insertion techniques and material selection. Three female and two male cephalic specimens of Caucasian ethnicity (73.6 ± 6.5 years; 21.41 ± 2.2 kg/m2) were included into this experimental split-face study. One facial side was treated with polycaprolactone (PCL) thread: 180 mm, bidirectional, 18G 100 mm cannula, 20 degrees trajectory, preauricular approach whereas the contralateral side was treated with polydioxanone (PDO) thread: 100 mm, bidirectional, 19G, 60 mm cannula, 50 degrees trajectory, infraorbital approach. Three-dimensional imaging outcome measures included vertical and horizontal skin displacement and volume changes at the nasolabial sulcus, at the labiomandibular sulcus, and along the jawline. Comparing PCL 180 mm 20 degrees to PDO 100 mm 50 degrees: vertical lifting effect 1.42 ± 2.63 mm versus 1.24 ± 1.88 mm (p = 0.906); horizontal lifting effect 3.42 ± 1.44 mm versus -2.02 ± 1.84 mm (p = 0.001); nasolabial volume change -0.80 ± 0.65 mL versus -0.52 ± 0.17 mL (p = 0.367); labiomandibular volume change -0.45 ± 0.42 mL versus -0.16 ± 0.16 mL (p = 0.191); jawline volume change 0.02 ± 0.43 mL versus -0.01 ± 0.21 mL (p = 0.892). The study provides objective evidence for the short-term effectiveness of facial suspension threads in treating the nasolabial folds. The results point toward a better aesthetic outcome when utilizing long facial suspension threads that can effect full-face changes as compared with short facial suspension threads.

Asian Long-Range Transport in Relation to Atmospheric Rivers in Northern California

The study investigates the effect of aerosol long-range transport on precipitation over Northern California during atmospheric river (AR) events in the 2017 cold season (January–April). ARs in 2017 were one of the strongest to date, and the intense precipitation associated with the ARs resulted in flooding, destruction of property, and contamination of water supplies. The Aerosol Optical Depth (AOD) from Moderate Resolution Imaging Spectroradiometer (MODIS) data shows Asian dust traveling across the Northern Pacific Ocean along with AR events. Aerosol measurements in California, provided by the Interagency Monitoring of Protected Visual Environments (IMPROVE), show that more Asian dust tends to be observed over the coast, while non-Asian/localized dust is observed inland. A mixture of Asian and localized dust is observed over the mountains, although higher amounts of both are observed in the spring (March–April). Back trajectory analysis confirms that Asian aerosols are transported along the air parcels, and each AR event has its own transport pattern in terms of horizontal advection and vertical lifting. Correlation between precipitation and aerosols is low. This suggests that aerosols contribute little to the decrease of local precipitation during the 2017 AR events.

A note on fibrations of $$G_2$$ G 2 -manifolds

In this note, we first give some constructions of torsion-free $$G_2$$ -structures on some topological product manifolds. Then we provide a sufficient condition of 3-Calabi–Yau fibrations for $$G_2$$ -manifolds. Next we study the Gukov–Yau–Zaslow horizontal lifting for hyperKahler firbations of $$G_2$$ -manifolds, and discuss when the Gukov-Yau-Zaslow metric on this fibration is a $$G_2$$ -metric.

Left Lie reduction for curves in homogeneous spaces

Let H be a closed subgroup of a connected finite-dimensional Lie group G, where the canonical projection π : G → G/H is a Riemannian submersion with respect to a bi-invariant Riemannian metric on G. Given a C∞ curve x : [a, b] → G/H, let $\tilde {x}:[a,b]\rightarrow G$ be the horizontal lifting of x with $\tilde {x}(a)=e$ , where e denotes the identity of G. When (G, H) is a Riemannian symmetric pair, we prove that the left Lie reduction $V(t):=\tilde x(t)^{-1}\dot {\tilde x}(t)$ of $\dot {\tilde x}(t)$ for t ∈ [a, b] can be identified with the parallel pullbackP(t) of the velocity vector $\dot {x}(t)$ from x(t) to x(a) along x. Then left Lie reductions are used to investigate Riemannian cubics, Riemannian cubics in tension and elastica in homogeneous spaces G/H. Simplifications of reduced equations are found when (G, H) is a Riemannian symmetric pair. These equations are compared with equations known for curves in Lie groups, focusing on the special case of Riemannian cubics in the 3-dimensional unit sphere S3.

Back School programme for nurses has reduced low back pain levels: A randomised controlled trial.

(i) To examine patient lifting techniques used by nurses, and (ii) to evaluate an effectiveness of the Spine Care for Nurses programme in chronic nonspecific low back pain syndrome reduction and the execution of proper patient lifting techniques. Millions of nurses around the world suffer from occupational-related chronic nonspecific low back pain (chronic nonspecific low back pain syndrome). Generally, low back pain in nurses is a result of increased pressure on the spine and can be associated with improperly conducted patient lifting techniques. A randomised controlled trial was conducted among 137 nurses with chronic nonspecific low back pain syndrome. Participants were randomised into an experimental and control group (experimental group n=67, control group n=70). Nurses in the experimental group attended the Spine Care for Nurses programme for 3months. The programme consisted of didactic education, spine-strengthening exercises and education on safe patient handling techniques. The control group only received a brief written lifestyle guidance. The Zebris WinSpine Triple Lumbar examination was used to analyse nurses' patient lifting techniques (horizontal and vertical lifting). The lumbar pain intensity was measured with a 0-100 visual analogue scale. The pre-intervention average chronic nonspecific low back pain syndrome intensity score on visual analogue scale decreased from 49.3 to the postintervention score of 7.5. The correct execution of vertical lifting techniques in the experimental group increased from 8.91%-97.01% (control group: 8.57% pre-intervention test and postintervention test 11.42%). The horizontal patient lifting technique pre-intervention increased from 10.44%-100% correct execution in the experimental group (control group: pre-intervention test 10.00% and postintervention test 11.42%). The Spine Care for Nurses programme significantly reduced chronic nonspecific low back pain syndrome and increased the number of properly executed horizontal and vertical patient lifting techniques in nurses. We recommend that healthcare organisations should consider the implementation of regular Spine Care for Nurses programmes as successful low back injury prevention programmes.

Preparation of phthalocyanine-bound myristoyl celluloses for photocurrent generation system

The influences of two structural modifications on the photocurrent generation performance of the Langmuir–Blodgett (LB) film of the 6-O-phthalocyaninyl cellulose derivative were investigated. These structural modifications were the substituent groups at the O-2 and O-3 positions, and the central metal of the phthalocyanine moiety. Specifically, 6-O-Zn/phthalocyaninyl- (8a) and Pd/phthalocyaninyl (8b) -2,3-di-O-myristoylcelluloses were prepared instead of 6-O-Zn/phthalocyaninyl-2,3-di-O-myristylcellulose (2). The LB monolayer film of compound 8a on an indium thin oxide electrode showed higher photocurrent generation performance than that of compound 2. This suggested that myristoyl groups (C-14 acyl groups) were more beneficial to photocurrent generation than myristyl groups (C-14 alkyl groups), as the substituent at the O-2 and O-3 positions. The LB monolayer film of compound 8b showed photocurrent generation from 500 to 700 nm, although a blue-shift in the Q-band maximum was observed. The photocurrent generation performance of compound 8b was significantly higher than that of compound 8a. This indicated that Pd was more beneficial to photocurrent generation than Zn. The film of compound 8b prepared by the horizontal lifting method showed better photocurrent generation performance than that prepared by the vertical dipping method. Consequently, compound 8b is a complementary material to the porphyrin-appended cellulose derivative (1) for photocurrent generation system.

Factors affecting photocurrent generation performances of Langmuir–Blodgett films of tetraphenylporphyrin-bound acyl celluloses

Various Langmuir–Blodgett (LB) films of tetraphenylporphyrin (TPP)-bound acyl celluloses with different degrees of substitution of the TPP groups (DSTPP) and different acyl groups were prepared. TPP-bound acyl celluloses with DSTPP values less than 0.38 and myristoyl groups as the O-2 and O-3 substituents were suitable for obtaining LB mono-layer films with high quantum yields. The horizontal lifting method was better than the vertical dipping method for the deposition of LB films. The number of layers in LB multi-layer films of TPP-bound myristoyl cellulose with a DSTPP of 0.36 also influenced the quantum yield, and the quantum yield of the LB di-layer film was higher than those of the LB mono- and tri-layer films. This information will be useful in the improvement of the photocurrent generation performances of LB films of TPP-bound acyl celluloses.

Modulate the Morphology and Spectroscopic Property of Gold Nanoparticle Arrays by Polymer-Assisted Thermal Treatment

In this article, we report the morphology modulation of gold nanoparticle (NP) arrays by polymer-assisted thermal treatment. Simultaneously, localized surface plasmon resonance (LSPR) UV–vis extinction (absorption plus scattering) of gold NP arrays was monitored and analyzed. First, through horizontal lifting, gold NP monolayers were transferred from a water/hexane interface to glass slides. After thin polymer films were spin-coated on the gold NP monolayers, thermal treatment was carried out, which results in apparent color changes in the obtained samples. The color changes could be attributed to the shift of the surface plasmon band (SPB), along with increasing gold NP size and interparticle distance. We found that different polymers show different effects on the modulation of gold NPs’ morphology, accompanied by different shifts of the SPB. Polymers with relatively lower glass transition temperatures (Tg), such as poly(methyl methacrylate), promoted gold NPs to merge into spheres, while polymers with r...

Formation of graphene oxide films at the liquid/liquid interface

A strategy of employing graphene oxide (GO) nanosheets to prepare large-area GO films is proposed in this work. The films are prepared by injecting GO suspension in a mixture of water and ethanol (H2O + EtOH) at the liquid/liquid (hexane/water, C6H14/H2O) interface and forming the GO films at the interface. After evaporation of C6H14, GO films at the air/(H2O + EtOH) interface are transferred onto solid substrates by the horizontal lifting deposition, and large area (2.5 cm × 2.5 cm) of homogeneous GO films with the thickness of 5.4 nm and the roughness of 3.6 nm is obtained. The formation scheme of the GO films at the C6H14/(H2O + EtOH) interface is discussed considering the density difference between the C6H14, (H2O + EtOH), and H2O, as well as the interaction between the GO nanosheets. This facile strategy paves a new path for preparation of large ultrathin GO films from GO nanosheets, which is of great importance for the preparation of GO-based materials to be used in supercapacitor electrodes, transparent conductive films and field-effect transistors.

Impact of the interfacial traps on the charge accumulation in organic transistors

A silver nanoparticles (NPs) self-assembled monolayer (SAM) was introduced in the pentacene organic field-effect transistors using modified Langmuir–Schäffer (horizontal lifting) technique, and its effect was being evaluated electrically using current–voltage (I−V) and impedance spectroscopy (IS) measurements. The I−V results showed a significant negative threshold voltage shift indicating that hole trapping phenomena exist inside the devices with about two orders higher in the contact resistance and an order lower in the effective mobility when a SAM was introduced. The IS measurements with the simulation of Maxwell–Wagner equivalent circuit revealed that the incorporation of the NPs SAM had a comparable negative voltage shift as in I–V measurements with a higher trapping time based on the simulation results.