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Go to Editorial ManagerReflective cracking is a serious issue that Adversely influences the performance and longevity of asphalt overlays over deteriorated pavements. This review Looks for the Technologies which used to reduce the reflection cracks propagation by insert a new Strategies and different design materials. This research dealt with many treatments such as: increasing the layer thickness of Hot Mix Asphalt (HMA), creating modified asphalt by adding polymers to asphalt, rubberizing asphalt, carbon black, sulfur and other different materials. Geosynthetic materials were studied and analyzed to evaluate their ability to increase the layer tensile strength and minimize the effect of reflection cracks such as geotextiles, geogrids, and Stress Absorbing Membrane Interlayers (SAMI). The research shows that the increasing of overlay asphalt layer thickness leads to durability development. On the other hand, using developed materials like Polymer-Modified Asphalt and Stress Absorbing Membrane Interlayers (SAMI) Strategies leads to increasing the service life of the repaired pavement. The conclusion indicated that the development of overlay asphalt layer thickness and layer reinforcement and applying advanced environmental systems can be improving the pavement performance. These Strategies can produce a perfect solution to prevent or reduce the reflection cracks in rigid and flexible pavement.
This paper discusses the development of a seven-band coherent wavelength-division multiplexing (WDM) system covering the T to U systems, aiming to enhance the capacity and system efficiency. Seven multiband systems (C+L, S+C+L, S+C+L+U, E+S+C+L, E+S+C+L+U, O+E+S+C+L+U, and T+O+E+S+C+L+U) are designed with 40 GBaud symbol rate, 50 GHz channel spacing, and dual-polarization (DP)-16QAM signaling. The analysis adopted the enhanced Gaussian noise model, considering the amplified spontaneous emission of inline optical amplifiers and nonlinear interference (NLI) from fiber nonlinear optics, including Kerr effect and stimulated Raman scattering (SRS) which it implemented using Matlab (Ver. 2020b) program. The results show that the optimal powers are -4, -5, -5, -4.5, -3.5, -6, and -4.5 dBm for the seven WDM systems, respectively. Further, with a fiber span length of 100 km, the C+L system has the longest transmission reach of 20 span. However, using S+C+L+U system gives the highest bit rate-distance product of 1619 Tbps.km. The O+E+S+C+L+U and T+O+E+S+C+L+U systems are designed with 50 km-span length to reduce the effect of NLI caused by the large numbers of channels (1060 and 1200, respectively).
Heritage buildings are part of the connection between the past and the present. By paying attention to their occupancy, we keep the present and future generations in touch with what our ancestors achieved, hence sustaining them being part of the living heritage. Restoration and renovation procedures must be carried out to make them capable of meeting contemporary needs, However, it is essential to recognize the architectural characteristics that resonate with long term occupants. This research focuses on the effect of design characteristics on the psychological relationship between heritage buildings and their occupants, through case studies of two heritage buildings in Baghdad. The first is the previous Theological college building of Al al-Bayt University of the 1920s, now the College of education for girls, and the second is the 19th century Ottoman Al-Qishla building. The study relies on conducting a questionnaire for the occupants about their response to design characteristics of each building. The questionnaire concluded that the design characteristics of the heritage building have a significant impact on the psychological response of its occupants. The majority of respondents indicated that characteristics such as clarity of function, clarity of elements, sense of security, privacy, and flexibility, were satisfactory. The majority of respondents expressed appreciation for heritage buildings, as well as positive evaluations and appreciation for the reflection of the past in these buildings, indicating that “architectural characteristics of the heritage building” has a significant impact on the psychological connection felt by the occupants of the heritage building.
A high-performance Mach-Zehnder interferometer (MZI) based all-optical switch using graphene on silicon nitride (Si3N4) is proposed and simulated. Graphene absorbs pump power (λ = 980 nm) on Si3N4 waveguide, generating heat. The heat affects the Si3N4 waveguide, causing a change in its refractive index due to thermo-optic effect. By tuning the probe phase (λ = 1550 nm) in the Si3N4 arm with graphene on top, all optical switching can then be carried out. An extinction ratio ranges of 13-25 dB and pump power range 20-270 mW. These findings demonstrate that our suggested configuration offers a useful integrated part for the creation of effective all-optical control devices on the insulator platform with a quick switching rate. Moreover, the suggested design might be able to achieve a wide bandwidth by utilizing an integrated MZI structure.
Recently, there is increasing interest in using the 18 THz bandwidth offered by S+C+L band to increase the transmission capacity of fiber communication systems. This leads to the generation of ultra-wideband (UWB) wavelength-division multiplexing (WDM) optical communication systems. In these advanced systems, stimulated Raman scattering (SRS) causes a power transfer from high-frequency channels to low-frequency channels. This effect leads to an increase in the nonlinear interference (NLI) between the UWB-WDM channels. Power optimization techniques are required to balance transfer power between band channels, thus increasing the maximum transmission reach (MTR) along with increasing system capacity. In this paper, the transmission performance of S+C+L band system operating with dual-polarization 16-QAM signaling is investigated using enhanced Gaussian noise model. The transmitter and receiver for each DP channel use a -polarized laser and incorporate two identical configurations, one for x- and the other for y-state of polarization (SOP). The results are presented for two values of symbol rate, 40 and 80 GBaud, where the system carries 360 (=160+80+120) and 180 (=80+40+60) channels, respectively. The results revel that the MTR of both cases is equal to 12 100 km-spans when the channel lunch power equals to -4 and -2 dBm, respectively. This work also shows the effect of NLI components as a function of the number of spans, channel spacing, and channel launch power. The results show that the cross-phase modulation component of the NLI has high accumulated value with transmission distance, while the self-phase modulation component is almost constant.
Mesopotamian cities were formed sometime during the fourth millennium BCE, and many of them continued to be inhabited as much as 3000 years. While urban characteristics of these cities has been extensively studied, the current article is concerned with exploring the inhabitants' daily experience in the city; a subject that has not been sufficiently explored despite its importance in urban studies. The objective is to expand the understanding of the relation between the ancient city and its occupants. The paper adopts the concept of the City Image as introduced in the seminal work of Kevin Lunch "Image of The City" in investigating aspects of the Mesopotamian city that qualifies it to form a strong mental Image for her citizens, derived from the legibility of its elements and the structure they form. Using a descriptive analytical method in reviewing previous literature, the research first clarifies the shared characters of Mesopotamian cities, and addresses the stature of the city in Mesopotamians' culture. I then specify the five urban elements of the city image as categorised by Lynch; paths, nodes, edges, districts and landmarks, in addition to addressing manifestations of the citizens' urban life in the Mesopotamian city. Afterward, visualization of the citizen's daily experience through the urban fabric of the city is provided, to arrive at a conclusion of the Legibility of the mental image of the Mesopotamian city in the perception of its citizens.
The fifth generation (5G) and beyond mobile networks support increasing number of users with increasing bit rate per users. This has encouraged researchers to propose coherent digital subcarrier multiplexing (SCM) point-to-multipoint (P2MP) architectures to reduce the cost and complexity of optical transport networks, particularly in the metro aggregation scenario. However, coherent optical receiver is relatively costly and complexity compared with a direct-detection (DD) counterpart due to the use of a synchronized local laser. This paper addresses design issues and performance investigation of intensity modulation/direct-detection (IM/DD) P2MP optical networks. P2MP architectures are designed using digital RF multisubcarrier (MSC) waveform embedded on the intensity of continuous-wave (CW) laser beside direct-detection scheme. The design covers C- and O-band operation using a wavelength-division multiplexing (WDM) architecture. Further single- and double-polarization (SP and DP) versions are reported for each type of the networks. All the architectures are built in Optisystem version 15 environment and simulated for different network parameters, under the assumption of 25 Gbps per subcarrier data rate. The main performance measures are maximum route reach and bit rate-distance product (BDP). The simulation results indicate that DD networks can replaced the coherent counterpart when number of subcarriers per optical channel is 4. Further, the O-band P2MP networks offer high values of maximum reach and BDP than C-band counterparts.
The strategy of reusing materials and architectural elements in new buildings and locations after extracting them from previous structures and sites, known historically as "spolia," is now an important approach in contemporary architectural project design. This strategy showcases a balance between tradition and innovation, transforming heritage elements into new architectural pieces that carry contemporary artistic and cultural values. The purpose of this research is to uncover the forms of this practice and the meanings or purposes associated with it, within a theoretical framework that serves as a tool for designers when dealing with such projects. The research reviews studies on the subject and extracts the most important terms, then moves on to analyse several worldwide case studies of contemporary projects that have applied the concept of spolia reuse. The purpose is to enrich the framework by highlighting the reused architectural elements and their new functions, as well as the meanings and interpretations linked to these cases. The research identifies key indicators, including respect for heritage, creative artistic expression, sustainability, and recycling. The aim of the article is to shed light on the importance and effectiveness of using the concept of spolia reuse in the design of modern architectural projects and to promote a sustainable and innovative architectural culture.
The security level and robustness of memristive image encryption techniques depend on the order and dynamics complexity of the memristive system. The grid multi-double-scroll (GMDS) chaotic system (CS) offers extremely rich dynamics but the implementation of high-order chaos needs large computation time. To overcome this limitation, researchers have proposed the use of muti-lower-order CSs to assist the encryption process individually. This scenario may reduce the security level since the non-friendly user may attack each involved CS independently. This paper proposes an effective six-dimensional (6D) memristive chaotic system constructed by combining 5D, 5D, and 7D GMDS chaotic systems. Each of the six chaotic sequences is generated from three sequences corresponding to two or three of the basic CSs. The combined CS shares the same total key parameters (initial values and design parameters associated with the three basic CSs) and this leads to a key space of 22392, the highest among the reported image encryption techniques. The combined CS is used to assist the operation of a proposed color image encryption scheme consisting of four sequential stages that perform compressive sensing, scrambling, DNA encoding, and diffusion, respectively. Simulation results validate the feasibility and robust security of the proposed encryption scheme.
In the last two decades Modern architecture of the 20th century has become a primary focus for numerous global organizations, researchers, and academics who aim to preserve and sustain it. The leading parties in this endeavor are UNESCO and the International DOCOMOMO. They recognize modern heritage as tangible, authentic, carrying exceptional features and modern characteristics that reflect values, shifts, and norms of its era. Therefore, Docomomo has identified key Modernist Merits as criteria to assess the authenticity of this heritage, while UNESCO has listed many modern buildings and sites on the World Heritage List. In this respect many Iraqi modernist buildings suffer from mishandling and poor interest. Numerous have been distorted, demolished, or are on the verge of disappearing. This reflects a lack of understanding their exceptional modernist values which are worthy of preservation, and thus inefficiency in managing this heritage. Given that Intervention in modernist heritage involves adhering to guidelines set by international organization, the vague connection between criteria of DOCOMOMO and those of UNESCO clouds the process. Therefore, this article focuses on addressing the relationship between the two organizations' sets of criteria and clarifying their connection. The authors also aimed to address the national Iraqi context by assessing selected cases of modernist heritage buildings by one of Iraq’s modernism pioneers, architect Qahtan Al-Madfai, against DOCOMOMO’s criteria for modernist merits, highlighting the originality of Iraqi modernist heritage.Using a descriptive analytical approach, the theoretical sections of the paper begin by exploring the principles and characteristics of modern architecture, followed by identifying the exceptional values of modernist buildings, defined by DOCOMOMO as Modernist Merits and linking them to UNESCO's criteria. The practical part includes an experts’ survey to assess the Modernist Merits of the selected sample of Al- Madfaies’ buildings.The research results showed that Qahtaan Al-Madfai’s architecture was distinguished by a high evaluation of two Merits (exceptional features): the technological feature and the artistic aesthetic feature. While the first was fairly preserved, the second feature was affected in some buildings as a result of the mismanagement of these buildings and the lack of awareness of their values.